Scippy

SCIP

Solving Constraint Integer Programs

Detailed Description

methods for handling symmetries by dynamic lexicographic ordering reduction

Author
Jasper van Doornmalen

This implements lexicographic reduction, which generalizes symresack propagation to work for non-binary variable domains, and is dynamified. Whereas static lexicographic reduction propagates that a vector \(x\) is lexicographically larger than its permuted counterpart (i.e., \(x \succeq \gamma(x)\) with \(\succeq\) being standard elementwise lexicographic comparison), the dynamic variant determines the variable vector ordering dynamically. Just as in orbital reduction (cf. symmetry_orbital.c), the variable order is chosen as the variables branched on from the root node to the focus node. Thus, in node \(\beta\), we propagate \(\sigma_\beta(x) \succeq \sigma_\beta(\gamma(x))\), where \(\sigma_\beta(\cdot)\) permutes and restricts the variable vector such that it corresponds to the branched variables in the order from the rooted path to \(\beta\).

See Section 4.1 and Example 11 in [vD,H]:
J. van Doornmalen, C. Hojny, "A Unified Framework for Symmetry Handling", preprint, 2023, https://doi.org/10.48550/arXiv.2211.01295.

For dynamic lexicographic reduction, it is crucial that the vectors \(\sigma_\beta(x)\) are the branching variables up to node \(\beta\) in the given order. Since SCIP can change the tree structure during solving (re-writing history), we store the original branching decisions at the moment they are made. See event_shadowtree.c .

Definition in file symmetry_lexred.c.

#include "blockmemshell/memory.h"
#include "scip/symmetry_lexred.h"
#include "scip/pub_cons.h"
#include "scip/pub_message.h"
#include "scip/pub_var.h"
#include "scip/struct_var.h"
#include "scip/type_var.h"
#include "scip/scip.h"
#include "scip/scip_branch.h"
#include "scip/scip_conflict.h"
#include "scip/scip_cons.h"
#include "scip/scip_copy.h"
#include "scip/scip_cut.h"
#include "scip/scip_general.h"
#include "scip/scip_lp.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_numerics.h"
#include "scip/scip_param.h"
#include "scip/scip_prob.h"
#include "scip/scip_probing.h"
#include "scip/scip_sol.h"
#include "scip/scip_var.h"
#include "scip/debug.h"
#include "scip/struct_scip.h"
#include "scip/struct_mem.h"
#include "scip/struct_tree.h"
#include "scip/symmetry.h"
#include "scip/event_shadowtree.h"
#include <string.h>

Go to the source code of this file.

Data Structures

struct  LexRedPermData
 
struct  NodeDepthBranchIndex
 
struct  VarArrayNodeDepthBranchIndex
 

Typedefs

typedef struct LexRedPermData LEXDATA
 
typedef struct NodeDepthBranchIndex NODEDEPTHBRANCHINDEX
 
typedef struct VarArrayNodeDepthBranchIndex VARARRAYNODEDEPTHBRANCHINDEX
 

Functions

static SCIP_RETCODE lexdataFree (SCIP *scip, LEXDATA **lexdata)
 
static SCIP_RETCODE lexdataCreate (SCIP *scip, SCIP_LEXREDDATA *masterdata, LEXDATA **lexdata, SCIP_VAR *const *vars, int nvars, int *perm, SYM_SYMTYPE symtype, SCIP_Real *permvardomaincenter, SCIP_Bool usedynamicorder, SCIP_Bool *success)
 
static SCIP_DECL_SORTINDCOMP (sortbynodedepthbranchindices)
 
static int varOrderGetIndex (int *varorder, int pos)
 
static SCIP_RETCODE getVarOrder (SCIP *scip, SCIP_LEXREDDATA *masterdata, LEXDATA *lexdata, NODEDEPTHBRANCHINDEX *nodedepthbranchindices, int nvarstotal, SCIP_VAR **branchvars, int nbranchvars, int *varorder, int *nselvars, int maxnselvars)
 
static SCIP_RETCODE getVarBounds (SCIP_VAR *var1, SCIP_VAR *var2, SCIP_Bool peekmode, int varidx1, int varidx2, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset, SCIP_Real *lb1, SCIP_Real *ub1, SCIP_Real *lb2, SCIP_Real *ub2)
 
static SCIP_Bool alwaysLTshiftedVars (SCIP *scip, SCIP_VAR *var1, SCIP_VAR *var2, SCIP_Real shift1, SCIP_Real shift2, SCIP_Bool isnegated, SCIP_Bool peekmode, int varidx1, int varidx2, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset)
 
static SCIP_Bool canGTshiftedVars (SCIP *scip, SCIP_VAR *var1, SCIP_VAR *var2, SCIP_Real shift1, SCIP_Real shift2, SCIP_Bool isnegated, SCIP_Bool peekmode, int varidx1, int varidx2, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset)
 
static SCIP_RETCODE propagateLowerBoundVar (SCIP *scip, SCIP_VAR *var1, SCIP_VAR *var2, SCIP_Real center1, SCIP_Real center2, SCIP_Bool isnegated, SCIP_Bool *infeasible, int *nreductions, SCIP_Bool peekmode, int varidx1, int varidx2, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset)
 
static SCIP_RETCODE propagateUpperBoundSymVar (SCIP *scip, SCIP_VAR *var1, SCIP_VAR *var2, SCIP_Real center1, SCIP_Real center2, SCIP_Bool isnegated, SCIP_Bool *infeasible, int *nreductions, SCIP_Bool peekmode, int varidx1, int varidx2, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset)
 
static SCIP_RETCODE propagateSelfReflectionVar (SCIP *scip, SCIP_VAR *var, SCIP_Real center, SCIP_Bool *infeasible, int *nreductions, SCIP_Bool peekmode, int varidx, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset)
 
static SCIP_RETCODE propagateVariablePair (SCIP *scip, SCIP_VAR *var1, SCIP_VAR *var2, SCIP_Real center1, SCIP_Real center2, SCIP_Bool isnegated, SCIP_Bool *infeasible, int *nreductions, SCIP_Bool peekmode, int varidx1, int varidx2, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset)
 
static SCIP_RETCODE peekStaticLexredIsFeasible (SCIP *scip, LEXDATA *lexdata, int *varorder, int nselvars, int fixi, int fixj, int fixrow, SCIP_Real fixvaluei, SCIP_Real fixvaluej, SCIP_Bool *peekfeasible, SCIP_Real *peeklbs, SCIP_Real *peekubs, SCIP_Bool *peekbdset)
 
static SCIP_RETCODE propagateStaticLexred (SCIP *scip, LEXDATA *lexdata, int *varorder, int nselvars, SCIP_Bool *infeasible, int *nreductions)
 
static SCIP_RETCODE propagateLexredDynamic (SCIP *scip, SCIP_LEXREDDATA *masterdata, LEXDATA *lexdata, NODEDEPTHBRANCHINDEX *nodedepthbranchindices, int nvarstotal, SCIP_VAR **branchvars, int nbranchvars, SCIP_Bool *infeasible, int *nreductions)
 
static SCIP_RETCODE propagateLexredStatic (SCIP *scip, SCIP_LEXREDDATA *masterdata, LEXDATA *lexdata, SCIP_Bool *infeasible, int *nreductions)
 
static SCIP_RETCODE propagateLexicographicReductionPerm (SCIP *scip, SCIP_LEXREDDATA *masterdata, LEXDATA *lexdata, NODEDEPTHBRANCHINDEX *nodedepthbranchindices, int nvarstotal, SCIP_VAR **branchvars, int nbranchvars, SCIP_Bool *infeasible, int *nreductions)
 
static SCIP_RETCODE shadowtreeFillNodeDepthBranchIndices (SCIP *scip, SCIP_LEXREDDATA *masterdata, NODEDEPTHBRANCHINDEX *nodedepthbranchindices, SCIP_VAR **branchvars, int *nbranchvars, SCIP_SHADOWTREE *shadowtree, SCIP_NODE *focusnode, SCIP_Bool *inforesolved)
 
static SCIP_RETCODE shadowtreeUndoNodeDepthBranchIndices (SCIP *scip, SCIP_LEXREDDATA *masterdata, NODEDEPTHBRANCHINDEX *nodedepthbranchindices, SCIP_VAR **branchvars, int *nbranchvars, SCIP_SHADOWTREE *shadowtree, SCIP_NODE *focusnode)
 
SCIP_RETCODE SCIPlexicographicReductionGetStatistics (SCIP *scip, SCIP_LEXREDDATA *masterdata, int *nred, int *ncutoff)
 
SCIP_RETCODE SCIPlexicographicReductionPrintStatistics (SCIP *scip, SCIP_LEXREDDATA *masterdata)
 
SCIP_RETCODE SCIPlexicographicReductionPropagate (SCIP *scip, SCIP_LEXREDDATA *masterdata, SCIP_Bool *infeasible, int *nred, SCIP_Bool *didrun)
 
SCIP_RETCODE SCIPlexicographicReductionAddPermutation (SCIP *scip, SCIP_LEXREDDATA *masterdata, SCIP_VAR **permvars, int npermvars, int *perm, SYM_SYMTYPE symtype, SCIP_Real *permvardomaincenter, SCIP_Bool usedynamicorder, SCIP_Bool *success)
 
SCIP_RETCODE SCIPlexicographicReductionReset (SCIP *scip, SCIP_LEXREDDATA *masterdata)
 
SCIP_RETCODE SCIPlexicographicReductionFree (SCIP *scip, SCIP_LEXREDDATA **masterdata)
 
SCIP_RETCODE SCIPincludeLexicographicReduction (SCIP *scip, SCIP_LEXREDDATA **masterdata, SCIP_EVENTHDLR *shadowtreeeventhdlr)
 

Typedef Documentation

◆ LEXDATA

typedef struct LexRedPermData LEXDATA

Definition at line 100 of file symmetry_lexred.c.

◆ NODEDEPTHBRANCHINDEX

Definition at line 125 of file symmetry_lexred.c.

◆ VARARRAYNODEDEPTHBRANCHINDEX

Function Documentation

◆ lexdataFree()

static SCIP_RETCODE lexdataFree ( SCIP scip,
LEXDATA **  lexdata 
)
static

frees dynamic lexicographic reduction propagator data

Parameters
scipSCIP data structure
lexdatapointer to individual lexicographic reduction propagator datas

Definition at line 144 of file symmetry_lexred.c.

References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPfreeBlockMemory, SCIPfreeBlockMemoryArray, SCIPhashmapFree(), SCIPreleaseVar(), SYM_SYMTYPE_SIGNPERM, and TRUE.

Referenced by SCIPlexicographicReductionReset().

◆ lexdataCreate()

static SCIP_RETCODE lexdataCreate ( SCIP scip,
SCIP_LEXREDDATA masterdata,
LEXDATA **  lexdata,
SCIP_VAR *const *  vars,
int  nvars,
int *  perm,
SYM_SYMTYPE  symtype,
SCIP_Real permvardomaincenter,
SCIP_Bool  usedynamicorder,
SCIP_Bool success 
)
static

creates dynamic lexicographic reduction propagator data

Fixed points are removed.

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
lexdatapointer to store data for permutation to be added
varsinput variables of the lexicographic reduction propagator
nvarsinput number of variables of the lexicographic reduction propagator
perminput permutation of the lexicographic reduction propagator
symtypetype of symmetries in perm
permvardomaincenterarray containing center point for each variable domain
usedynamicorderwhether a dynamic variable order shall be used
successto store whether the component is successfully added

Definition at line 222 of file symmetry_lexred.c.

References FALSE, NULL, LexRedPermData::nvars, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPactivateShadowTree(), SCIPallocBlockMemory, SCIPallocBlockMemoryArray, SCIPallocBufferArray, SCIPblkmem(), SCIPcaptureVar(), SCIPfreeBlockMemory, SCIPfreeBufferArray, SCIPhashmapCreate(), SCIPhashmapExists(), SCIPhashmapInsertInt(), SCIPisTransformed(), SCIPmarkDoNotMultaggrVar(), SCIPvarIsTransformed(), SYM_SYMTYPE_PERM, LexRedPermData::symtype, and TRUE.

Referenced by SCIPlexicographicReductionAddPermutation().

◆ SCIP_DECL_SORTINDCOMP()

static SCIP_DECL_SORTINDCOMP ( sortbynodedepthbranchindices  )
static

comparator used in the getVarOrder() function, for sorting an array of NODEDEPTHBRANCHINDEX by depth, then by index

Warning
this function is only meant to be used in the getVarOrder() function
Precondition
datapointer is populated with a VARARRAYNODEDEPTHBRANCHINDEX pointer
the comparator is only called on entries with set (depth, index)-information
the (depth, index)-informations are all different

result: 0: the same index is compared, so the (depth, index)-informations are the same -1: the depth of ind1 is smaller than the depth of ind2, or it's equal and the index is smaller 1: the depth of ind2 is smaller than the depth of ind1, or it's equal and the index is smaller

Definition at line 422 of file symmetry_lexred.c.

References NodeDepthBranchIndex::index, VarArrayNodeDepthBranchIndex::masterdata, NodeDepthBranchIndex::nodedepth, VarArrayNodeDepthBranchIndex::nodedepthbranchindices, SCIPhashmapGetImageInt(), LexRedPermData::vars, and VarArrayNodeDepthBranchIndex::vars.

◆ varOrderGetIndex()

static int varOrderGetIndex ( int *  varorder,
int  pos 
)
static

return the index of a variable at a specific position of a variable order

Parameters
varordervariable order (or NULL)
posposition for which index is returned

Definition at line 466 of file symmetry_lexred.c.

References NULL.

Referenced by peekStaticLexredIsFeasible(), and propagateStaticLexred().

◆ getVarOrder()

static SCIP_RETCODE getVarOrder ( SCIP scip,
SCIP_LEXREDDATA masterdata,
LEXDATA lexdata,
NODEDEPTHBRANCHINDEX nodedepthbranchindices,
int  nvarstotal,
SCIP_VAR **  branchvars,
int  nbranchvars,
int *  varorder,
int *  nselvars,
int  maxnselvars 
)
static

gets the variable ordering based on the branching decisions at the node

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
lexdatapointer to data for this permutation
nodedepthbranchindicesarray with (depth, index)-information per variable in rooted path to focus node
nvarstotallength of that array
branchvarsarray populated with variables branched on in the symvarmap hashset
nbranchvarsnumber of elements in branchvars array
varorderarray to populate with variable order
nselvarspointer to number of variables in the ordering
maxnselvarsmaximal size of the number of selected variables

Definition at line 481 of file symmetry_lexred.c.

References VarArrayNodeDepthBranchIndex::masterdata, VarArrayNodeDepthBranchIndex::nodedepthbranchindices, NULL, LexRedPermData::nvars, SCIP_OKAY, SCIPhashmapExists(), SCIPhashmapGetImageInt(), SCIPsortInd(), LexRedPermData::varmap, LexRedPermData::vars, and VarArrayNodeDepthBranchIndex::vars.

Referenced by propagateLexredDynamic().

◆ getVarBounds()

static SCIP_RETCODE getVarBounds ( SCIP_VAR var1,
SCIP_VAR var2,
SCIP_Bool  peekmode,
int  varidx1,
int  varidx2,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset,
SCIP_Real lb1,
SCIP_Real ub1,
SCIP_Real lb2,
SCIP_Real ub2 
)
static

gerts local variable bounds or reads bound from peek data

Parameters
var1first variable in comparison
var2second variable in comparison
peekmodewhether function is called in peek mode
varidx1index of var1 (or NULL)
varidx2index of var2 (or NULL)
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)
lb1pointer to store lower bound of var1
ub1pointer to store upper bound of var1
lb2pointer to store lower bound of var2
ub2pointer to store upper bound of var2

Definition at line 590 of file symmetry_lexred.c.

References NULL, SCIP_OKAY, SCIPvarGetLbLocal(), and SCIPvarGetUbLocal().

Referenced by alwaysLTshiftedVars(), canGTshiftedVars(), propagateLowerBoundVar(), propagateSelfReflectionVar(), propagateStaticLexred(), and propagateUpperBoundSymVar().

◆ alwaysLTshiftedVars()

static SCIP_Bool alwaysLTshiftedVars ( SCIP scip,
SCIP_VAR var1,
SCIP_VAR var2,
SCIP_Real  shift1,
SCIP_Real  shift2,
SCIP_Bool  isnegated,
SCIP_Bool  peekmode,
int  varidx1,
int  varidx2,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset 
)
static

returns whether a shifted variable is always smaller than another shifted variable

Shifts are always (var - shift).

Parameters
scipSCIP data structure
var1first variable in comparison
var2second variable in comparison
shift1shift of var1
shift2shift of var2
isnegatedwhether shift of var2 is negated
peekmodewhether function is called in peek mode
varidx1index of var1 (or NULL)
varidx2index of var2 (or NULL)
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)

Definition at line 644 of file symmetry_lexred.c.

References FALSE, getVarBounds(), NULL, SCIP_CALL_ABORT, SCIP_Real, SCIPisLT(), and TRUE.

Referenced by peekStaticLexredIsFeasible(), and propagateVariablePair().

◆ canGTshiftedVars()

static SCIP_Bool canGTshiftedVars ( SCIP scip,
SCIP_VAR var1,
SCIP_VAR var2,
SCIP_Real  shift1,
SCIP_Real  shift2,
SCIP_Bool  isnegated,
SCIP_Bool  peekmode,
int  varidx1,
int  varidx2,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset 
)
static

returns whether a shifted variable can be greater than another shifted variable

Shifts are always (var - shift).

Parameters
scipSCIP data structure
var1first variable in comparison
var2second variable in comparison
shift1shift of var1
shift2shift of var2
isnegatedwhether shift of var2 is negated
peekmodewhether function is called in peek mode
varidx1index of var1 (or NULL)
varidx2index of var2 (or NULL)
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)

Definition at line 691 of file symmetry_lexred.c.

References FALSE, getVarBounds(), NULL, SCIP_CALL_ABORT, SCIP_Real, SCIPisGT(), and TRUE.

Referenced by peekStaticLexredIsFeasible(), and propagateStaticLexred().

◆ propagateLowerBoundVar()

static SCIP_RETCODE propagateLowerBoundVar ( SCIP scip,
SCIP_VAR var1,
SCIP_VAR var2,
SCIP_Real  center1,
SCIP_Real  center2,
SCIP_Bool  isnegated,
SCIP_Bool infeasible,
int *  nreductions,
SCIP_Bool  peekmode,
int  varidx1,
int  varidx2,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset 
)
static

propagates lower bound of first variable in relation x >= y for shifted variables

Parameters
scipSCIP data structure
var1first variable in pair
var2second variable in pair
center1center of var1 (original var domain)
center2center of var2 (original var domain)
isnegatedwhether var2 is negated by symmetry
infeasiblepointer to store whether infeasibility is found
nreductionspointer to store number of reductions
peekmodewhether function is called in peek mode
varidx1index of var1 (or NULL)
varidx2index of var2 (or NULL)
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)

Definition at line 735 of file symmetry_lexred.c.

References FALSE, getVarBounds(), NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPisLT(), SCIPtightenVarLb(), SCIPvarGetName(), and TRUE.

Referenced by peekStaticLexredIsFeasible(), and propagateVariablePair().

◆ propagateUpperBoundSymVar()

static SCIP_RETCODE propagateUpperBoundSymVar ( SCIP scip,
SCIP_VAR var1,
SCIP_VAR var2,
SCIP_Real  center1,
SCIP_Real  center2,
SCIP_Bool  isnegated,
SCIP_Bool infeasible,
int *  nreductions,
SCIP_Bool  peekmode,
int  varidx1,
int  varidx2,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset 
)
static

propagates upper bound of second variable in relation x >= y for shifted variables

Parameters
scipSCIP data structure
var1first variable in pair
var2second variable in pair
center1center of var1 (original var domain)
center2center of var2 (original var domain)
isnegatedwhether var2 is negated by symmetry
infeasiblepointer to store whether infeasibility is found
nreductionspointer to store number of reductions
peekmodewhether function is called in peek mode
varidx1index of var1 (or NULL)
varidx2index of var2 (or NULL)
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)

Definition at line 822 of file symmetry_lexred.c.

References FALSE, getVarBounds(), NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPisLT(), SCIPtightenVarLb(), SCIPtightenVarUb(), SCIPvarGetName(), and TRUE.

Referenced by peekStaticLexredIsFeasible(), and propagateVariablePair().

◆ propagateSelfReflectionVar()

static SCIP_RETCODE propagateSelfReflectionVar ( SCIP scip,
SCIP_VAR var,
SCIP_Real  center,
SCIP_Bool infeasible,
int *  nreductions,
SCIP_Bool  peekmode,
int  varidx,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset 
)
static

propagates x - c >= c - x

Parameters
scipSCIP data structure
varvariable
centercenter of var (original var domain)
infeasiblepointer to store whether infeasibility is found
nreductionspointer to store number of reductions
peekmodewhether function is called in peek mode
varidxindex of var (or NULL)
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)

Definition at line 932 of file symmetry_lexred.c.

References FALSE, getVarBounds(), NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPisLT(), SCIPtightenVarLb(), SCIPvarGetName(), and TRUE.

Referenced by propagateVariablePair().

◆ propagateVariablePair()

static SCIP_RETCODE propagateVariablePair ( SCIP scip,
SCIP_VAR var1,
SCIP_VAR var2,
SCIP_Real  center1,
SCIP_Real  center2,
SCIP_Bool  isnegated,
SCIP_Bool infeasible,
int *  nreductions,
SCIP_Bool  peekmode,
int  varidx1,
int  varidx2,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset 
)
static

propagates lexicographic order for one pair of symmetric variables

Parameters
scipSCIP data structure
var1first variable in pair
var2second variable in pair
center1center of var1 (original var domain)
center2center of var2 (original var domain)
isnegatedwhether var2 is negated by symmetry
infeasiblepointer to store whether infeasibility is found
nreductionspointer to store number of reductions
peekmodewhether function is called in peek mode
varidx1index of var1 (or NULL)
varidx2index of var2 (or NULL)
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)

Definition at line 1003 of file symmetry_lexred.c.

References alwaysLTshiftedVars(), NULL, propagateLowerBoundVar(), propagateSelfReflectionVar(), propagateUpperBoundSymVar(), SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), and TRUE.

Referenced by propagateStaticLexred().

◆ peekStaticLexredIsFeasible()

static SCIP_RETCODE peekStaticLexredIsFeasible ( SCIP scip,
LEXDATA lexdata,
int *  varorder,
int  nselvars,
int  fixi,
int  fixj,
int  fixrow,
SCIP_Real  fixvaluei,
SCIP_Real  fixvaluej,
SCIP_Bool peekfeasible,
SCIP_Real peeklbs,
SCIP_Real peekubs,
SCIP_Bool peekbdset 
)
static

checks if the static lexred with a certain variable ordering is feasible in the hypothetical scenario where variables with indices i and j are fixed to fixvalue (i.e., peeking)

Parameters
scipSCIP data structure
lexdatapointer to data for this permutation
varorderarray populated with variable order (or NULL for static propagation)
nselvarsnumber of variables in the ordering
fixivariable index of left fixed column
fixjvariable index of right fixed column
fixrowrow index in var ordering, from which to start peeking
fixvalueivalue on which variables i is fixed
fixvaluejvalue on which variables j is fixed
peekfeasiblepointer to store whether this is feasible or not
peeklbslower bounds of variables in peek mode (or NULL)
peekubsupper bounds of variables in peek mode (or NULL)
peekbdsetwhether peek bounds have been set (or NULL)

Definition at line 1076 of file symmetry_lexred.c.

References alwaysLTshiftedVars(), canGTshiftedVars(), FALSE, LexRedPermData::invperm, NULL, LexRedPermData::nvars, LexRedPermData::perm, propagateLowerBoundVar(), propagateUpperBoundSymVar(), SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SYM_SYMTYPE_SIGNPERM, LexRedPermData::symtype, TRUE, LexRedPermData::vardomaincenter, varOrderGetIndex(), and LexRedPermData::vars.

Referenced by propagateStaticLexred().

◆ propagateStaticLexred()

static SCIP_RETCODE propagateStaticLexred ( SCIP scip,
LEXDATA lexdata,
int *  varorder,
int  nselvars,
SCIP_Bool infeasible,
int *  nreductions 
)
static

propagates static lexicographic reduction with specified variable ordering

Parameters
scipSCIP data structure
lexdatapointer to data for this permutation
varorderarray populated with variable order (or NULL if static propagation)
nselvarsnumber of variables in the ordering
infeasiblepointer to store whether the problem is infeasible
nreductionspointer to store the number of found domain reductions

Definition at line 1204 of file symmetry_lexred.c.

References canGTshiftedVars(), FALSE, getVarBounds(), LexRedPermData::invperm, NULL, LexRedPermData::nvars, peekStaticLexredIsFeasible(), LexRedPermData::perm, propagateVariablePair(), SCIP_Bool, SCIP_CALL, SCIP_ERROR, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_BINARY, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_IMPLINT, SCIP_VARTYPE_INTEGER, SCIPallocBufferArray, SCIPerrorMessage, SCIPfreeBufferArray, SCIPisIntegral(), SCIPsymEQ(), SCIPsymGE(), SCIPsymGT(), SCIPsymLE(), SCIPtightenVarLb(), SCIPtightenVarUb(), SCIPvarGetType(), SYM_SYMTYPE_SIGNPERM, LexRedPermData::symtype, TRUE, LexRedPermData::vardomaincenter, varOrderGetIndex(), and LexRedPermData::vars.

Referenced by propagateLexredDynamic(), and propagateLexredStatic().

◆ propagateLexredDynamic()

static SCIP_RETCODE propagateLexredDynamic ( SCIP scip,
SCIP_LEXREDDATA masterdata,
LEXDATA lexdata,
NODEDEPTHBRANCHINDEX nodedepthbranchindices,
int  nvarstotal,
SCIP_VAR **  branchvars,
int  nbranchvars,
SCIP_Bool infeasible,
int *  nreductions 
)
static

propagation method for a dynamic lexicographic reduction

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
lexdatapointer to data for this permutation
nodedepthbranchindicesarray with (depth, index)-information per variable in rooted path to focus node
nvarstotallength of nodedepthbranchindices array
branchvarsarray populated with variables branched on
nbranchvarsnumber of elements in branchvars array
infeasiblepointer to store whether the problem is infeasible
nreductionspointer to store the number of found domain reductions

Definition at line 1536 of file symmetry_lexred.c.

References getVarOrder(), LexRedPermData::isdynamic, NULL, LexRedPermData::nvars, propagateStaticLexred(), SCIP_CALL, SCIP_OKAY, SCIPallocBufferArray, and SCIPfreeBufferArray.

Referenced by propagateLexicographicReductionPerm().

◆ propagateLexredStatic()

static SCIP_RETCODE propagateLexredStatic ( SCIP scip,
SCIP_LEXREDDATA masterdata,
LEXDATA lexdata,
SCIP_Bool infeasible,
int *  nreductions 
)
static

propagation method for a dynamic lexicographic reduction

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
lexdatapointer to data for this permutation
infeasiblepointer to store whether the problem is infeasible
nreductionspointer to store the number of found domain reductions

Definition at line 1586 of file symmetry_lexred.c.

References LexRedPermData::isdynamic, NULL, LexRedPermData::nvars, propagateStaticLexred(), SCIP_CALL, and SCIP_OKAY.

Referenced by propagateLexicographicReductionPerm().

◆ propagateLexicographicReductionPerm()

static SCIP_RETCODE propagateLexicographicReductionPerm ( SCIP scip,
SCIP_LEXREDDATA masterdata,
LEXDATA lexdata,
NODEDEPTHBRANCHINDEX nodedepthbranchindices,
int  nvarstotal,
SCIP_VAR **  branchvars,
int  nbranchvars,
SCIP_Bool infeasible,
int *  nreductions 
)
static

propagation method for applying dynamic lexicographic reduction for a single permutation

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
lexdatapointer to data for this permutation
nodedepthbranchindicesarray with (depth, index)-information per variable in rooted path to focus node
nvarstotallength of that array
branchvarsarray populated with variables branched on
nbranchvarsnumber of elements in branchvars array
infeasiblepointer to store whether the problem is infeasible
nreductionspointer to store the number of found domain reductions

Definition at line 1614 of file symmetry_lexred.c.

References FALSE, LexRedPermData::isdynamic, NULL, propagateLexredDynamic(), propagateLexredStatic(), SCIP_CALL, and SCIP_OKAY.

Referenced by SCIPlexicographicReductionPropagate().

◆ shadowtreeFillNodeDepthBranchIndices()

static SCIP_RETCODE shadowtreeFillNodeDepthBranchIndices ( SCIP scip,
SCIP_LEXREDDATA masterdata,
NODEDEPTHBRANCHINDEX nodedepthbranchindices,
SCIP_VAR **  branchvars,
int *  nbranchvars,
SCIP_SHADOWTREE shadowtree,
SCIP_NODE focusnode,
SCIP_Bool inforesolved 
)
static

populates array with information of first variable change

Precondition
assuming nodedepthbranchindices is initially clean
Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
nodedepthbranchindicesarray to populate
branchvarsarray to populate with variables branched on
nbranchvarsnumber of elements in branchvars array
shadowtreepointer to shadow tree structure
focusnodefocusnode to which the rooted path is evaluated
inforesolvedpointer to store whether information is successfully resolved

Definition at line 1657 of file symmetry_lexred.c.

References SCIP_ShadowNode::branchingdecisions, SCIP_ShadowNode::children, FALSE, NodeDepthBranchIndex::index, SCIP_ShadowNode::nbranchingdecisions, SCIP_ShadowNode::nchildren, NodeDepthBranchIndex::nodedepth, NULL, SCIP_ShadowNode::parent, SCIP_OKAY, SCIPhashmapGetImageInt(), SCIPnodeGetDepth(), SCIPshadowTreeGetShadowNode(), SCIPvarIsTransformed(), SCIPwarningMessage(), TRUE, and SCIP_ShadowBoundUpdate::var.

Referenced by SCIPlexicographicReductionPropagate().

◆ shadowtreeUndoNodeDepthBranchIndices()

static SCIP_RETCODE shadowtreeUndoNodeDepthBranchIndices ( SCIP scip,
SCIP_LEXREDDATA masterdata,
NODEDEPTHBRANCHINDEX nodedepthbranchindices,
SCIP_VAR **  branchvars,
int *  nbranchvars,
SCIP_SHADOWTREE shadowtree,
SCIP_NODE focusnode 
)
static

cleans nodedepthbranchindices array

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
nodedepthbranchindicesarray populated by nodedepthbranchindices to clean
branchvarsarray populated with variables branched on
nbranchvarsnumber of elements in branchvars array
shadowtreepointer to shadow tree structure
focusnodefocusnode to which the rooted path is evaluated

Definition at line 1773 of file symmetry_lexred.c.

References SCIP_ShadowNode::branchingdecisions, SCIP_ShadowNode::children, NodeDepthBranchIndex::index, SCIP_ShadowNode::nbranchingdecisions, SCIP_ShadowNode::nchildren, NodeDepthBranchIndex::nodedepth, NULL, SCIP_ShadowNode::parent, SCIP_OKAY, SCIPhashmapExists(), SCIPhashmapGetImageInt(), SCIPnodeGetDepth(), SCIPshadowTreeGetShadowNode(), and SCIP_ShadowBoundUpdate::var.

Referenced by SCIPlexicographicReductionPropagate().

◆ SCIPlexicographicReductionGetStatistics()

SCIP_RETCODE SCIPlexicographicReductionGetStatistics ( SCIP scip,
SCIP_LEXREDDATA masterdata,
int *  nred,
int *  ncutoff 
)

prints lexicographic reduction propagation data

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
nredtotal number of reductions applied
ncutofftotal number of cutoffs applied

Definition at line 1871 of file symmetry_lexred.c.

References NULL, and SCIP_OKAY.

Referenced by SCIP_DECL_TABLEOUTPUT().

◆ SCIPlexicographicReductionPrintStatistics()

SCIP_RETCODE SCIPlexicographicReductionPrintStatistics ( SCIP scip,
SCIP_LEXREDDATA masterdata 
)

prints lexicographic reduction propagation data

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator

Definition at line 1889 of file symmetry_lexred.c.

References NULL, SCIP_OKAY, SCIP_VERBLEVEL_HIGH, and SCIPverbMessage().

Referenced by SCIPdisplaySymmetryStatistics().

◆ SCIPlexicographicReductionPropagate()

SCIP_RETCODE SCIPlexicographicReductionPropagate ( SCIP scip,
SCIP_LEXREDDATA masterdata,
SCIP_Bool infeasible,
int *  nred,
SCIP_Bool didrun 
)

applies lexicographic reduction propagation

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
infeasiblepointer to store whether infeasibility is found
nredpointer to store the number of domain reductions
didruna global pointer maintaining if any symmetry propagator has run only set this to TRUE when a reduction is found, never set to FALSE

Definition at line 1922 of file symmetry_lexred.c.

References FALSE, VarArrayNodeDepthBranchIndex::nodedepthbranchindices, NULL, propagateLexicographicReductionPerm(), SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPallocCleanBufferArray, SCIPfreeCleanBufferArray, SCIPgetFocusNode(), SCIPgetShadowTree(), shadowtreeFillNodeDepthBranchIndices(), shadowtreeUndoNodeDepthBranchIndices(), and TRUE.

Referenced by propagateSymmetry().

◆ SCIPlexicographicReductionAddPermutation()

SCIP_RETCODE SCIPlexicographicReductionAddPermutation ( SCIP scip,
SCIP_LEXREDDATA masterdata,
SCIP_VAR **  permvars,
int  npermvars,
int *  perm,
SYM_SYMTYPE  symtype,
SCIP_Real permvardomaincenter,
SCIP_Bool  usedynamicorder,
SCIP_Bool success 
)

adds permutation for lexicographic reduction propagation

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
permvarsvariable array of the permutation
npermvarsnumber of variables in that array
permpermutation
symtypetype of symmetries in perm
permvardomaincenterarray containing center point for each variable domain
usedynamicorderwhether a dynamic variable order shall be used
successto store whether the component is successfully added

Definition at line 2033 of file symmetry_lexred.c.

References FALSE, lexdataCreate(), NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBlockMemoryArray, SCIPcalcMemGrowSize(), SCIPisTransformed(), SCIPreallocBlockMemoryArray, SYM_SYMTYPE_PERM, and SYM_SYMTYPE_SIGNPERM.

Referenced by addOrbitopesDynamic(), and tryAddOrbitalRedLexRed().

◆ SCIPlexicographicReductionReset()

SCIP_RETCODE SCIPlexicographicReductionReset ( SCIP scip,
SCIP_LEXREDDATA masterdata 
)

resets lexicographic reduction propagation (removes all permutations)

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator

Definition at line 2097 of file symmetry_lexred.c.

References FALSE, lexdataFree(), NULL, SCIP_CALL, SCIP_OKAY, SCIPfreeBlockMemoryArrayNull, and SCIPhashmapFree().

Referenced by resetDynamicSymmetryHandling(), and SCIPlexicographicReductionFree().

◆ SCIPlexicographicReductionFree()

SCIP_RETCODE SCIPlexicographicReductionFree ( SCIP scip,
SCIP_LEXREDDATA **  masterdata 
)

frees lexicographic reduction data

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator

Definition at line 2135 of file symmetry_lexred.c.

References NULL, SCIP_CALL, SCIP_OKAY, SCIPfreeBlockMemory, and SCIPlexicographicReductionReset().

Referenced by SCIP_DECL_PROPFREE().

◆ SCIPincludeLexicographicReduction()

SCIP_RETCODE SCIPincludeLexicographicReduction ( SCIP scip,
SCIP_LEXREDDATA **  masterdata,
SCIP_EVENTHDLR shadowtreeeventhdlr 
)

initializes structures needed for lexicographic reduction propagation

This is only done exactly once.

Parameters
scipSCIP data structure
masterdatapointer to global data for lexicographic reduction propagator
shadowtreeeventhdlrpointer to the shadow tree eventhdlr

Definition at line 2158 of file symmetry_lexred.c.

References FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPallocBlockMemory, SCIPcheckStage(), and TRUE.

Referenced by SCIPincludePropSymmetry().