SCIP
Solving Constraint Integer Programs
Detailed Description
methods for presolving
Definition in file presolve.c.
#include "blockmemshell/memory.h"#include "scip/presolve.h"#include "scip/prob.h"#include "scip/pub_implics.h"#include "scip/pub_message.h"#include "scip/pub_var.h"#include "scip/scip_mem.h"#include "scip/scip_message.h"#include "scip/scip_numerics.h"#include "scip/scip_tree.h"#include "scip/struct_mem.h"#include "scip/struct_scip.h"#include "scip/tree.h"Go to the source code of this file.
Macros | |
| #define | CLEARRATIO 0.8 |
Functions | |
| static void | collectNonBinaryVBoundData (SCIP *scip, SCIP_VAR *var, int varidx, int pos, int nredvars, SCIP_Real *bounds, SCIP_Bool *boundtypes, SCIP_Real *newbounds, int *counts, int *countnonzeros, int *ncountnonzeros, int *issetvar, int nvars, int *foundbin, int *foundnonbin, int *implidx, int *nimplidx, SCIP_Real *lastbounds) |
| static void | collectNonBinaryImplicationData (SCIP *scip, SCIP_VAR *var, int varidx, int pos, int nredvars, SCIP_Bool value, SCIP_Real *bounds, SCIP_Bool *boundtypes, SCIP_Real *newbounds, int *counts, int *countnonzeros, int *ncountnonzeros, int *issetvar, int nvars, int *foundbin, int *foundnonbin, int *implidx, int *nimplidx, SCIP_Real *lastbounds) |
| static void | collectBinaryCliqueData (SCIP_VAR *var, int varidx, int pos, int nredvars, SCIP_Bool value, SCIP_Real *bounds, SCIP_Bool *boundtypes, SCIP_Real *newbounds, int *counts, int *countnonzeros, int *ncountnonzeros, int *issetvar, int nvars, int *foundbin, int *implidx, int *nimplidx) |
| SCIP_RETCODE | SCIPshrinkDisjunctiveVarSet (SCIP *scip, SCIP_VAR **vars, SCIP_Real *bounds, SCIP_Bool *boundtypes, SCIP_Bool *redundants, int nvars, int *nredvars, int *nglobalred, SCIP_Bool *setredundant, SCIP_Bool *glbinfeas, SCIP_Bool fullshortening) |
Macro Definition Documentation
◆ CLEARRATIO
| #define CLEARRATIO 0.8 |
Definition at line 952 of file presolve.c.
Referenced by SCIPshrinkDisjunctiveVarSet().
Function Documentation
◆ collectNonBinaryVBoundData()
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static |
collect variable bound information for a variable set reduction and global implication; only variable which have the vartype != SCIP_VARTYPE_BINARY have variable bounds
- Parameters
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scip SCIP data structure var set variable varidx for lower bound set variable index, for upper bound set variable index - number of variables
pos variables's position in bdchinfos nredvars number of reduced variables so far bounds array of bounds where one of them must be fullfilled boundtypes array of bound types newbounds array of implied bounds(, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) counts array of number of implication on a bound (, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) countnonzeros array to store the indices of non-zero entries in the counts array ncountnonzeros pointer to store the number of non-zero entries in the counts array issetvar array containing for set variables the position in the current set, or 0 if it is not a set variable or -1, if it is a redundant(i.e. implies another set variable) set variables(, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) nvars number of problem variables foundbin pointer to store the lowest index of a binary implication variable when found foundnonbin pointer to store the lowest index of a non-binary implication variable when found implidx array to store the variable indices (for upper bound 'nvars' is added to the index) which are implied nimplidx pointer to store the number of implied variables lastbounds array to remember last implied bounds before taken the current variable into account, first nvars for lower bound, second nvars for upper bound
this array is used when a set variable got redundant, because it implies another set variable, and we need to correct the counts array
Definition at line 47 of file presolve.c.
References MIN, NULL, SCIP_INVALID, SCIP_Real, SCIP_VARTYPE_BINARY, SCIPdebugMsg, SCIPisFeasEQ(), SCIPisFeasGT(), SCIPisFeasLT(), SCIPisZero(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetNVlbs(), SCIPvarGetNVubs(), SCIPvarGetProbindex(), SCIPvarGetType(), SCIPvarGetUbGlobal(), SCIPvarGetVlbCoefs(), SCIPvarGetVlbConstants(), SCIPvarGetVlbVars(), SCIPvarGetVubCoefs(), SCIPvarGetVubConstants(), SCIPvarGetVubVars(), SCIPvarIsBinary(), and w.
Referenced by SCIPshrinkDisjunctiveVarSet().
◆ collectNonBinaryImplicationData()
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static |
collect non-binary implication data for variable set reduction and global bound implications; only variable which have the vartype SCIP_VARTYPE_BINARY have implications, otherwise the implications are saved as variable bounds
- Parameters
-
scip SCIP data structure var set variable varidx for lower bound set variable index, for upper bound set variable index + number of variables pos variables's position in bdchinfos nredvars number of reduced variables so far value value used for clique and implication info bounds array of bounds where one of them must be fullfilled boundtypes array of bound types newbounds array of implied bounds(, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) counts array of number of implication on a bound (, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) countnonzeros array to store the indices of non-zero entries in the counts array ncountnonzeros pointer to store the number of non-zero entries in the counts array issetvar array containing for set variables the position in the current set, or 0 if it is not a set variable or -1, if it is a redundant(i.e. implies another set variable) set variables(, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) nvars number of problem variables foundbin pointer to store the lowest index of a binary implication variable when found foundnonbin pointer to store the lowest index of a non-binary implication variable when found implidx array to store the variable indices (for upper bound 'nvars' is added to the index) which are implied nimplidx pointer to store the number of implied variables lastbounds array to remember last implied bounds before taken the current variable into account, first nvars for lower bound, second nvars for upper bound
this array is used when a set variable got redundant, because it implies another set variable, and we need to correct the counts array
Definition at line 585 of file presolve.c.
References MIN, NULL, SCIP_BOUNDTYPE_UPPER, SCIP_INVALID, SCIP_Real, SCIP_VARTYPE_BINARY, SCIPdebugMsg, SCIPisFeasEQ(), SCIPisFeasGE(), SCIPisFeasLE(), SCIPvarGetImplBounds(), SCIPvarGetImplTypes(), SCIPvarGetImplVars(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetNImpls(), SCIPvarGetProbindex(), SCIPvarGetType(), SCIPvarGetUbGlobal(), SCIPvarIsBinary(), and w.
Referenced by SCIPshrinkDisjunctiveVarSet().
◆ collectBinaryCliqueData()
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static |
collect clique data on binary variables for variable set reduction and global bound implications
- Parameters
-
var set variable varidx for lower bound set variable index, for upper bound set variable index - number of variables
pos variables's position in bdchinfos nredvars number of reduced variables so far value value used for clique and implication info bounds array of bounds where one of them must be fullfilled boundtypes array of bound types newbounds array of implied bounds(, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) counts array of number of implication on a bound (, size is two times number of variables, first half for implied lower bounds, second for implied upper bounds) countnonzeros array to store the indices of non-zero entries in the counts array ncountnonzeros pointer to store the number of non-zero entries in the counts array issetvar array containing for set variables the position in the current set, or 0 if it is not a set variable, or -1, if it is a redundant (i.e. implies another set variable) set variable (the size of the array is two times the number of variables, first half for implied lower bounds, second for implied upper bounds) nvars number of problem variables foundbin pointer to store the lowest index of a binary implication variable when found implidx array to store the variable indices (for upper bound 'nvars' is added to the index) which are implied nimplidx pointer to store the number of implied variables
Definition at line 813 of file presolve.c.
References MIN, NULL, SCIP_Bool, SCIPcliqueGetNVars(), SCIPcliqueGetValues(), SCIPcliqueGetVars(), SCIPdebugMessage, SCIPvarGetCliques(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetNCliques(), SCIPvarGetProbindex(), SCIPvarGetUbGlobal(), SCIPvarIsBinary(), and w.
Referenced by SCIPshrinkDisjunctiveVarSet().