Infeasibility Analysis

Detailed Description

functions for analyzing infeasibility of a model (IIS, MinUC), see also How to deduce reasons for infeasibility in SCIP

Functions
SCIP_RETCODE	SCIPtransformMinUC (SCIP *scip, SCIP_Bool *success)
SCIP_Real	SCIPiisGetTime (SCIP_IIS *iis)
SCIP_Bool	SCIPiisIsSubscipInfeasible (SCIP_IIS *iis)
SCIP_Bool	SCIPiisIsSubscipIrreducible (SCIP_IIS *iis)
SCIP_Longint	SCIPiisGetNNodes (SCIP_IIS *iis)
void	SCIPiisSetSubscipInfeasible (SCIP_IIS *iis, SCIP_Bool infeasible)
void	SCIPiisSetSubscipIrreducible (SCIP_IIS *iis, SCIP_Bool irreducible)
void	SCIPiisAddNNodes (SCIP_IIS *iis, SCIP_Longint nnodes)
SCIP_RANDNUMGEN *	SCIPiisGetRandnumgen (SCIP_IIS *iis)
SCIP *	SCIPiisGetSubscip (SCIP_IIS *iis)
SCIP_CONS *	SCIPiisGetSubscipCons (SCIP_IIS *iis, SCIP_CONS *cons)
SCIP_VAR *	SCIPiisGetSubscipVar (SCIP_IIS *iis, SCIP_VAR *var)
SCIP_HASHMAP *	SCIPiisGetVarsmap (SCIP_IIS *iis)
SCIP_HASHMAP *	SCIPiisGetConssmap (SCIP_IIS *iis)
SCIP_RETCODE	SCIPgenerateIIS (SCIP *scip)
SCIP_IIS *	SCIPgetIIS (SCIP *scip)

Function Documentation

SCIPtransformMinUC()

SCIP_RETCODE SCIPtransformMinUC	(	SCIP *	scip,
		SCIP_Bool *	success
	)

transforms the current problem into a MinUC problem (minimizing the number of unsatisfied constraints), a CIP generalization of the MinULR (min. unsatisfied linear relations) problem

Parameters

scip	SCIP data structure
success	pointer to store whether all constraints could be transformed

Definition at line 2312 of file cons_superindicator.c.

References FALSE, NULL, SCIP_CALL, SCIP_INVALIDCALL, SCIP_MAXSTRLEN, SCIP_OBJSENSE_MINIMIZE, SCIP_OKAY, SCIP_STAGE_PROBLEM, SCIP_VARTYPE_BINARY, SCIPaddCons(), SCIPaddVar(), SCIPchgVarBranchPriority(), SCIPchgVarObj(), SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetName(), SCIPconsIsChecked(), SCIPconsIsDynamic(), SCIPconsIsEnforced(), SCIPconsIsInitial(), SCIPconsIsLocal(), SCIPconsIsPropagated(), SCIPconsIsRemovable(), SCIPconsIsSeparated(), SCIPconsIsStickingAtNode(), SCIPcreateConsSuperindicator(), SCIPcreateVar(), SCIPdebugMsg, SCIPdelCons(), SCIPduplicateBufferArray, SCIPerrorMessage, SCIPfreeBufferArray, SCIPgetConss(), SCIPgetNConss(), SCIPgetNegatedVar(), SCIPgetStage(), SCIPgetVarsData(), SCIPreleaseCons(), SCIPreleaseVar(), SCIPsetObjsense(), SCIPsnprintf(), SCIPvarGetBranchPriority(), and TRUE.

Referenced by SCIP_DECL_DIALOGEXEC().

SCIPiisGetTime()

SCIP_Real SCIPiisGetTime

(

SCIP_IIS *

iis

)

gets time in seconds used in the IIS calculations

gets time in seconds used in the IIS

Parameters

iis

IIS

Definition at line 933 of file iisfinder.c.

References SCIP_IIS::iistime, NULL, and SCIPclockGetTime().

Referenced by additionFilterBatch(), deletionFilterBatch(), execIISfinderGreedy(), SCIPiisfinderInfoMessage(), SCIPiisGenerate(), SCIPiisGreedyMakeIrreducible(), and setLimits().

SCIPiisIsSubscipInfeasible()

SCIP_Bool SCIPiisIsSubscipInfeasible

(

SCIP_IIS *

iis

)

Gets whether the IIS subscip is currently infeasible.

Parameters

iis	IIS data structure

Definition at line 943 of file iisfinder.c.

References SCIP_IIS::infeasible, and NULL.

Referenced by additionFilterBatch(), deletionFilterBatch(), and SCIPiisGreedyMakeIrreducible().

SCIPiisIsSubscipIrreducible()

SCIP_Bool SCIPiisIsSubscipIrreducible

(

SCIP_IIS *

iis

)

Gets whether the IIS subscip is irreducible.

Parameters

iis	IIS data structure

Definition at line 953 of file iisfinder.c.

References SCIP_IIS::irreducible, and NULL.

SCIPiisGetNNodes()

SCIP_Longint SCIPiisGetNNodes

(

SCIP_IIS *

iis

)

Gets the number of nodes in the IIS solve.

Parameters

iis	IIS data structure

Definition at line 963 of file iisfinder.c.

References SCIP_IIS::nnodes, and NULL.

Referenced by additionFilterBatch(), deletionFilterBatch(), execIISfinderGreedy(), SCIPiisfinderInfoMessage(), SCIPiisGenerate(), SCIPiisGreedyMakeIrreducible(), and setLimits().

SCIPiisSetSubscipInfeasible()

void SCIPiisSetSubscipInfeasible	(	SCIP_IIS *	iis,
		SCIP_Bool	infeasible
	)

Sets the flag that states whether the IIS subscip is currently infeasible.

Parameters

iis	IIS data structure
infeasible	The new infeasibility status of the IIS subscip

Definition at line 973 of file iisfinder.c.

References SCIP_IIS::infeasible, and NULL.

Referenced by additionFilterBatch(), and deletionSubproblem().

SCIPiisSetSubscipIrreducible()

void SCIPiisSetSubscipIrreducible	(	SCIP_IIS *	iis,
		SCIP_Bool	irreducible
	)

Sets the flag that states whether the IIS subscip is irreducible.

Parameters

iis	IIS data structure
irreducible	The new irreducible status of the IIS

Definition at line 983 of file iisfinder.c.

References SCIP_IIS::irreducible, and NULL.

Referenced by execIISfinderGreedy(), SCIPiisGenerate(), and SCIPiisGreedyMakeIrreducible().

SCIPiisAddNNodes()

void SCIPiisAddNNodes	(	SCIP_IIS *	iis,
		SCIP_Longint	nnodes
	)

Increments the number of nodes in the IIS solve.

Parameters

iis	IIS data structure
nnodes	The number of nodes to add to the IIS

Definition at line 993 of file iisfinder.c.

References nnodes, SCIP_IIS::nnodes, and NULL.

Referenced by additionSubproblem(), and deletionSubproblem().

SCIPiisGetRandnumgen()

SCIP_RANDNUMGEN * SCIPiisGetRandnumgen

(

SCIP_IIS *

iis

)

get the randnumgen of the IIS

Parameters

iis	pointer to the IIS

Definition at line 1003 of file iisfinder.c.

References NULL, and SCIP_IIS::randnumgen.

Referenced by additionFilterBatch(), and deletionFilterBatch().

SCIPiisGetSubscip()

SCIP * SCIPiisGetSubscip

(

SCIP_IIS *

iis

)

get the subscip of an IIS

Parameters

iis	pointer to the IIS

Definition at line 1012 of file iisfinder.c.

References NULL, and SCIP_IIS::subscip.

Referenced by additionFilterBatch(), additionSubproblem(), deletionFilterBatch(), deletionSubproblem(), execIISfinderGreedy(), SCIP_DECL_DIALOGEXEC(), SCIPiisfinderInfoMessage(), and SCIPiisGreedyMakeIrreducible().

SCIPiisGetSubscipCons()

SCIP_CONS * SCIPiisGetSubscipCons	(	SCIP_IIS *	iis,
		SCIP_CONS *	cons
	)

get the constraint in the IIS subscip corresponding to the given main constraint, or NULL if it was removed

Parameters

iis	pointer to the IIS
cons	constraint from the original model

Definition at line 1022 of file iisfinder.c.

References SCIP_IIS::conssmap, NULL, and SCIPhashmapGetImage().

SCIPiisGetSubscipVar()

SCIP_VAR * SCIPiisGetSubscipVar	(	SCIP_IIS *	iis,
		SCIP_VAR *	var
	)

get the variable in the IIS subscip corresponding to the given main variable, or NULL if it became redundant

get the variable in the IIS subscip corresponding to an original variable, or NULL if it does not exist

Parameters

iis	pointer to the IIS
var	variable from the original model

Definition at line 1033 of file iisfinder.c.

References NULL, SCIPhashmapGetImage(), and SCIP_IIS::varsmap.

SCIPiisGetVarsmap()

SCIP_HASHMAP * SCIPiisGetVarsmap

(

SCIP_IIS *

iis

)

get the varsmap of an IIS

Parameters

iis	pointer to the IIS

Definition at line 1043 of file iisfinder.c.

References NULL, and SCIP_IIS::varsmap.

SCIPiisGetConssmap()

SCIP_HASHMAP * SCIPiisGetConssmap

(

SCIP_IIS *

iis

)

get the conssmap of an IIS

Parameters

iis	pointer to the IIS

Definition at line 1052 of file iisfinder.c.

References SCIP_IIS::conssmap, and NULL.

SCIPgenerateIIS()

SCIP_RETCODE SCIPgenerateIIS

(

SCIP *

scip

)

the execution method that iterates over the IIS finder plugins

Parameters

scip	SCIP data structure

Definition at line 148 of file scip_iisfinder.c.

References NULL, SCIP_CALL, SCIP_OKAY, and SCIPiisGenerate().

Referenced by SCIP_DECL_DIALOGEXEC().

SCIPgetIIS()

SCIP_IIS * SCIPgetIIS

(

SCIP *

scip

)

Gets the IIS storage.

Returns

the SCIP_IIS iis storage.

Precondition

This method can be called if scip is in one of the following stages:

• SCIP_STAGE_INIT
• SCIP_STAGE_PROBLEM
• SCIP_STAGE_TRANSFORMING
• SCIP_STAGE_TRANSFORMED
• SCIP_STAGE_INITPRESOLVE
• SCIP_STAGE_PRESOLVING
• SCIP_STAGE_EXITPRESOLVE
• SCIP_STAGE_PRESOLVED
• SCIP_STAGE_INITSOLVE
• SCIP_STAGE_SOLVING
• SCIP_STAGE_SOLVED
• SCIP_STAGE_EXITSOLVE
• SCIP_STAGE_FREETRANS

See SCIP_STAGE for a complete list of all possible solving stages.

Parameters

scip	SCIP data structure

Definition at line 232 of file scip_iisfinder.c.

References FALSE, SCIP_CALL_ABORT, SCIPcheckStage, and TRUE.

Referenced by SCIP_DECL_DIALOGEXEC(), and SCIPiisGenerate().