Scippy

SCIP

Solving Constraint Integer Programs

cons_superindicator.h File Reference

Detailed Description

constraint handler for indicator constraints over arbitrary constraint types

Author
Ambros Gleixner
Frederic Pythoud

Superindicator constraints are constraints of the form

\[ x_i = 1 \Rightarrow C(x) \]

where $ x_i $ is a binary variable and $ C(\dot) $ a constraint. The superindicator constraint is satisfied if and only if x_i is zero or C is satisfied.

Definition in file cons_superindicator.h.

#include "scip/scip.h"

Go to the source code of this file.

Functions

SCIP_RETCODE SCIPincludeConshdlrSuperindicator (SCIP *scip)
 
SCIP_RETCODE SCIPcreateConsSuperindicator (SCIP *scip, SCIP_CONS **cons, const char *name, SCIP_VAR *binvar, SCIP_CONS *slackcons, SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode)
 
SCIP_RETCODE SCIPcreateConsBasicSuperindicator (SCIP *scip, SCIP_CONS **cons, const char *name, SCIP_VAR *binvar, SCIP_CONS *slackcons)
 
SCIP_VARSCIPgetBinaryVarSuperindicator (SCIP_CONS *cons)
 
SCIP_CONSSCIPgetSlackConsSuperindicator (SCIP_CONS *cons)
 
SCIP_RETCODE SCIPtransformMinUC (SCIP *scip, SCIP_Bool *success)
 
 SCIP_DECL_DIALOGEXEC (SCIPdialogExecChangeMinUC)
 

Function Documentation

SCIP_RETCODE SCIPincludeConshdlrSuperindicator ( SCIP scip)

creates the handler for superindicator constraints and includes it in SCIP

Parameters
scipSCIP data structure
SCIP_RETCODE SCIPcreateConsSuperindicator ( SCIP scip,
SCIP_CONS **  cons,
const char *  name,
SCIP_VAR binvar,
SCIP_CONS slackcons,
SCIP_Bool  initial,
SCIP_Bool  separate,
SCIP_Bool  enforce,
SCIP_Bool  check,
SCIP_Bool  propagate,
SCIP_Bool  local,
SCIP_Bool  dynamic,
SCIP_Bool  removable,
SCIP_Bool  stickingatnode 
)

creates and captures a superindicator constraint

Note
the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
Parameters
scipSCIP data structure
conspointer to hold the created constraint
namename of constraint
binvarpointer to the indicator constraint
slackconsconstraint corresponding to the handled constraint
initialshould the LP relaxation of constraint be in the initial LP? Usually set to TRUE. Set to FALSE for 'lazy constraints'.
separateshould the constraint be separated during LP processing? Usually set to TRUE.
enforceshould the constraint be enforced during node processing? TRUE for model constraints, FALSE for additional, redundant constraints.
checkshould the constraint be checked for feasibility? TRUE for model constraints, FALSE for additional, redundant constraints.
propagateshould the constraint be propagated during node processing? Usually set to TRUE.
localis constraint only valid locally? Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints.
dynamicis constraint subject to aging? Usually set to FALSE. Set to TRUE for own cuts which are separated as constraints.
removableshould the relaxation be removed from the LP due to aging or cleanup? Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'.
stickingatnodeshould the constraint always be kept at the node where it was added, even if it may be moved to a more global node? Usually set to FALSE. Set to TRUE to for constraints that represent node data.
SCIP_RETCODE SCIPcreateConsBasicSuperindicator ( SCIP scip,
SCIP_CONS **  cons,
const char *  name,
SCIP_VAR binvar,
SCIP_CONS slackcons 
)

creates and captures a superindicator constraint in its most basic version, i. e., all constraint flags are set to their basic value as explained for the method SCIPcreateConsSuperindicator(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h

See also
SCIPcreateConsSuperindicator() for information about the basic constraint flag configuration
Note
the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
Parameters
scipSCIP data structure
conspointer to hold the created constraint
namename of constraint
binvarpointer to the indicator constraint
slackconsconstraint corresponding to the handled constraint
SCIP_VAR* SCIPgetBinaryVarSuperindicator ( SCIP_CONS cons)

gets binary variable corresponding to the superindicator constraint

Parameters
conssuperindicator constraint
SCIP_CONS* SCIPgetSlackConsSuperindicator ( SCIP_CONS cons)

gets the slack constraint corresponding to the superindicator constraint

Parameters
conssuperindicator constraint
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
scipSCIP data structure
successpointer to store whether all constraints could be transformed
SCIP_DECL_DIALOGEXEC ( SCIPdialogExecChangeMinUC  )

dialog execution method for the SCIPtransformMinUC() command