Detailed Description

constraint handler for indicator constraints

Author: Marc Pfetsch

An indicator constraint is given by a binary variable $z$ and an inequality $ax \leq b$ . It states that if $z = 1$ then $ax \leq b$ holds.

This constraint is handled by adding a slack variable $s:\; ax - s \leq b$ with $s \geq 0$ . The constraint is enforced by fixing $s$ to 0 if $z = 1$ .

Note: The constraint only implements an implication not an equivalence, i.e., it does not ensure that if $ax \leq b$ or equivalently if holds.

This constraint is equivalent to a linear constraint $ax - s \leq b$ and an SOS1 constraint on $z$ and $s$ (at most one should be nonzero). In the indicator context we can, however, separate more inequalities.

The name indicator apparently comes from CPLEX.

Definition in file cons_indicator.h.

#include "scip/scip.h"

Go to the source code of this file.

Functions
SCIP_RETCODE	SCIPincludeConshdlrIndicator (SCIP *scip)

SCIP_RETCODE	SCIPcreateConsIndicator (SCIP scip, SCIP_CONS cons, const char name, SCIP_VAR binvar, int nvars, SCIP_VAR vars, SCIP_Real vals, SCIP_Real rhs, 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	SCIPcreateConsBasicIndicator (SCIP scip, SCIP_CONS cons, const char name, SCIP_VAR binvar, int nvars, SCIP_VAR vars, SCIP_Real vals, SCIP_Real rhs)

SCIP_RETCODE	SCIPcreateConsIndicatorLinCons (SCIP scip, SCIP_CONS cons, const char name, SCIP_VAR binvar, SCIP_CONS lincons, SCIP_VAR *slackvar, 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	SCIPcreateConsBasicIndicatorLinCons (SCIP scip, SCIP_CONS cons, const char name, SCIP_VAR binvar, SCIP_CONS lincons, SCIP_VAR *slackvar)

SCIP_RETCODE	SCIPaddVarIndicator (SCIP scip, SCIP_CONS cons, SCIP_VAR *var, SCIP_Real val)

SCIP_CONS *	SCIPgetLinearConsIndicator (SCIP_CONS *cons)

SCIP_RETCODE	SCIPsetLinearConsIndicator (SCIP scip, SCIP_CONS cons, SCIP_CONS *lincons)

SCIP_RETCODE	SCIPsetBinaryVarIndicator (SCIP scip, SCIP_CONS cons, SCIP_VAR *binvar)

SCIP_VAR *	SCIPgetBinaryVarIndicator (SCIP_CONS *cons)

SCIP_VAR *	SCIPgetSlackVarIndicator (SCIP_CONS *cons)

SCIP_Bool	SCIPisViolatedIndicator (SCIP scip, SCIP_CONS cons, SCIP_SOL *sol)

SCIP_RETCODE	SCIPmakeIndicatorFeasible (SCIP scip, SCIP_CONS cons, SCIP_SOL sol, SCIP_Bool changed)

SCIP_RETCODE	SCIPmakeIndicatorsFeasible (SCIP scip, SCIP_CONSHDLR conshdlr, SCIP_SOL sol, SCIP_Bool changed)

SCIP_RETCODE	SCIPaddLinearConsIndicator (SCIP scip, SCIP_CONSHDLR conshdlr, SCIP_CONS *lincons)

SCIP_RETCODE	SCIPaddRowIndicator (SCIP scip, SCIP_CONSHDLR conshdlr, SCIP_ROW *row)

Function Documentation

SCIP_RETCODE SCIPincludeConshdlrIndicator ( SCIP * scip )

creates the handler for indicator constraints and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 6125 of file cons_indicator.c.

References CONFLICTHDLR_DESC, CONFLICTHDLR_NAME, CONFLICTHDLR_PRIORITY, CONSHDLR_CHECKPRIORITY, CONSHDLR_DELAYPRESOL, CONSHDLR_DELAYPROP, CONSHDLR_DELAYSEPA, CONSHDLR_DESC, CONSHDLR_EAGERFREQ, CONSHDLR_ENFOPRIORITY, CONSHDLR_MAXPREROUNDS, CONSHDLR_NAME, CONSHDLR_NEEDSCONS, CONSHDLR_PROP_TIMING, CONSHDLR_PROPFREQ, CONSHDLR_SEPAFREQ, CONSHDLR_SEPAPRIORITY, DEFAULT_ADDCOUPLING, DEFAULT_ADDCOUPLINGCONS, DEFAULT_ADDOPPOSITE, DEFAULT_BRANCHINDICATORS, DEFAULT_CONFLICTSUPGRADE, DEFAULT_DUALREDUCTIONS, DEFAULT_ENFORCECUTS, DEFAULT_FORCERESTART, DEFAULT_GENERATEBILINEAR, DEFAULT_GENLOGICOR, DEFAULT_MAXCONDITIONALTLP, DEFAULT_MAXCOUPLINGVALUE, DEFAULT_MAXSEPACUTS, DEFAULT_MAXSEPACUTSROOT, DEFAULT_NOLINCONSCONT, DEFAULT_REMOVEINDICATORS, DEFAULT_RESTARTFRAC, DEFAULT_SCALESLACKVAR, DEFAULT_SEPAALTERNATIVELP, DEFAULT_SEPACOUPLINGCUTS, DEFAULT_SEPACOUPLINGLOCAL, DEFAULT_SEPACOUPLINGVALUE, DEFAULT_TRYSOLFROMCOVER, DEFAULT_TRYSOLUTIONS, DEFAULT_UPDATEBOUNDS, DEFAULT_USEOTHERCONSS, EVENTHDLR_BOUND_DESC, EVENTHDLR_BOUND_NAME, EVENTHDLR_RESTART_DESC, EVENTHDLR_RESTART_NAME, FALSE, initConshdlrData(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_REAL_MAX, SCIPaddBoolParam(), SCIPaddIntParam(), SCIPaddRealParam(), SCIPallocMemory, SCIPerrorMessage, SCIPincludeConflicthdlrBasic(), SCIPincludeConshdlrBasic(), SCIPincludeEventhdlrBasic(), SCIPsetConflicthdlrFree(), SCIPsetConshdlrCopy(), SCIPsetConshdlrDelete(), SCIPsetConshdlrDisable(), SCIPsetConshdlrEnable(), SCIPsetConshdlrExit(), SCIPsetConshdlrExitsol(), SCIPsetConshdlrFree(), SCIPsetConshdlrGetNVars(), SCIPsetConshdlrGetVars(), SCIPsetConshdlrInit(), SCIPsetConshdlrInitlp(), SCIPsetConshdlrInitpre(), SCIPsetConshdlrInitsol(), SCIPsetConshdlrParse(), SCIPsetConshdlrPresol(), SCIPsetConshdlrPrint(), SCIPsetConshdlrProp(), SCIPsetConshdlrResprop(), SCIPsetConshdlrSepa(), SCIPsetConshdlrTrans(), and TRUE.

Referenced by SCIP_DECL_CONSHDLRCOPY(), and SCIPincludeDefaultPlugins().

SCIP_RETCODE SCIPcreateConsIndicator	(	SCIP *	scip,
		SCIP_CONS **	cons,
		const char *	name,
		SCIP_VAR *	binvar,
		int	nvars,
		SCIP_VAR **	vars,
		SCIP_Real *	vals,
		SCIP_Real	rhs,
		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 an indicator constraint

Note: binvar is checked to be binary only later. This enables a change of the type in procedures reading an instance.; the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()

Parameters

scip	SCIP data structure
cons	pointer to hold the created constraint (indicator or quadratic)
name	name of constraint
binvar	binary indicator variable (or NULL)
nvars	number of variables in the inequality
vars	array with variables of inequality (or NULL)
vals	values of variables in inequality (or NULL)
rhs	rhs of the inequality
initial	should the LP relaxation of constraint be in the initial LP? Usually set to TRUE.
separate	should the constraint be separated during LP processing? Usually set to TRUE.
enforce	should the constraint be enforced during node processing? TRUE for model constraints, FALSE for additional, redundant constraints.
check	should the constraint be checked for feasibility? TRUE for model constraints, FALSE for additional, redundant constraints.
propagate	should the constraint be propagated during node processing? Usually set to TRUE.
local	is constraint only valid locally? Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints.
dynamic	is constraint subject to aging? Usually set to FALSE. Set to TRUE for own cuts which are separated as constraints.
removable	should 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'.
stickingatnode	should 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.

Definition at line 6366 of file cons_indicator.c.

References consdataCreate(), CONSHDLR_NAME, FALSE, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_INVALIDDATA, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_IMPLINT, SCIPaddCoefLinear(), SCIPaddCons(), SCIPaddVar(), SCIPceil(), SCIPconsAddUpgradeLocks(), SCIPconsGetNUpgradeLocks(), SCIPconshdlrGetData(), SCIPcreateCons(), SCIPcreateConsLinear(), SCIPcreateConsQuadratic(), SCIPcreateVar(), SCIPerrorMessage, SCIPfindConshdlr(), SCIPinfinity(), SCIPisIntegral(), SCIPisZero(), SCIPmarkDoNotMultaggrVar(), SCIPreleaseCons(), SCIPreleaseVar(), SCIPsnprintf(), SCIPvarGetType(), SCIPvarIsIntegral(), and TRUE.

Referenced by createIndicatorConstraint(), readIndicators(), SCIP_DECL_CONSINITPRE(), SCIPcreateConsBasicIndicator(), and upgradeIndicatorSuperindicator().

SCIP_RETCODE SCIPcreateConsBasicIndicator	(	SCIP *	scip,
		SCIP_CONS **	cons,
		const char *	name,
		SCIP_VAR *	binvar,
		int	nvars,
		SCIP_VAR **	vars,
		SCIP_Real *	vals,
		SCIP_Real	rhs
	)

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

See Also: SCIPcreateConsIndicator() 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

scip	SCIP data structure
cons	pointer to hold the created constraint (indicator or quadratic)
name	name of constraint
binvar	binary indicator variable (or NULL)
nvars	number of variables in the inequality
vars	array with variables of inequality (or NULL)
vals	values of variables in inequality (or NULL)
rhs	rhs of the inequality

Definition at line 6562 of file cons_indicator.c.

References FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPcreateConsIndicator(), and TRUE.

SCIP_RETCODE SCIPcreateConsIndicatorLinCons	(	SCIP *	scip,
		SCIP_CONS **	cons,
		const char *	name,
		SCIP_VAR *	binvar,
		SCIP_CONS *	lincons,
		SCIP_VAR *	slackvar,
		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 an indicator constraint with given linear constraint and slack variable

Note: binvar is checked to be binary only later. This enables a change of the type in procedures reading an instance.; we assume that slackvar actually appears in lincons and we also assume that it takes the role of a slack variable!; the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()

Parameters

scip	SCIP data structure
cons	pointer to hold the created constraint
name	name of constraint
binvar	binary indicator variable (or NULL)
lincons	linear constraint
slackvar	slack variable
initial	should the LP relaxation of constraint be in the initial LP? Usually set to TRUE.
separate	should the constraint be separated during LP processing? Usually set to TRUE.
enforce	should the constraint be enforced during node processing? TRUE for model constraints, FALSE for additional, redundant constraints.
check	should the constraint be checked for feasibility? TRUE for model constraints, FALSE for additional, redundant constraints.
propagate	should the constraint be propagated during node processing? Usually set to TRUE.
local	is constraint only valid locally? Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints.
dynamic	is constraint subject to aging? Usually set to FALSE. Set to TRUE for own cuts which are separated as constraints.
removable	should 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'.
stickingatnode	should 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.

Definition at line 6591 of file cons_indicator.c.

References consdataCreate(), CONSHDLR_NAME, FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_IMPLINT, SCIPconsAddUpgradeLocks(), SCIPconsGetHdlr(), SCIPconsGetNUpgradeLocks(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPcreateCons(), SCIPcreateConsQuadratic(), SCIPerrorMessage, SCIPfindConshdlr(), SCIPgetNVarsLinear(), SCIPgetVarsLinear(), SCIPmarkDoNotMultaggrVar(), SCIPvarGetType(), and TRUE.

Referenced by createSubSCIP(), readIndicators(), SCIP_DECL_CONSCOPY(), SCIP_DECL_CONSPARSE(), and SCIPcreateConsBasicIndicatorLinCons().

SCIP_RETCODE SCIPcreateConsBasicIndicatorLinCons	(	SCIP *	scip,
		SCIP_CONS **	cons,
		const char *	name,
		SCIP_VAR *	binvar,
		SCIP_CONS *	lincons,
		SCIP_VAR *	slackvar
	)

creates and captures an indicator constraint with given linear constraint and slack variable in its most basic version, i. e., all constraint flags are set to their basic value as explained for the method SCIPcreateConsIndicator(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h

Note: binvar is checked to be binary only later. This enables a change of the type in procedures reading an instance.; we assume that slackvar actually appears in lincons and we also assume that it takes the role of a slack variable!; the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()

See Also: SCIPcreateConsIndicatorLinCons() 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

scip	SCIP data structure
cons	pointer to hold the created constraint
name	name of constraint
binvar	binary indicator variable (or NULL)
lincons	linear constraint
slackvar	slack variable

Definition at line 6735 of file cons_indicator.c.

References FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPcreateConsIndicatorLinCons(), and TRUE.

SCIP_RETCODE SCIPaddVarIndicator	(	SCIP *	scip,
		SCIP_CONS *	cons,
		SCIP_VAR *	var,
		SCIP_Real	val
	)

adds variable to the inequality of the indicator constraint

Parameters

scip	SCIP data structure
cons	indicator constraint
var	variable to add to the inequality
val	value of variable

Definition at line 6754 of file cons_indicator.c.

References CONSHDLR_NAME, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_VARTYPE_CONTINUOUS, SCIPaddCoefLinear(), SCIPchgVarType(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconshdlrGetName(), SCIPisIntegral(), SCIPvarGetType(), and SCIPvarIsIntegral().

SCIP_CONS* SCIPgetLinearConsIndicator ( SCIP_CONS * cons )

gets the linear constraint corresponding to the indicator constraint (may be NULL)

Parameters

cons	indicator constraint

Definition at line 6785 of file cons_indicator.c.

References CONSHDLR_NAME, NULL, SCIPconsGetData(), SCIPconsGetHdlr(), and SCIPconshdlrGetName().

Referenced by computeRanks(), createSubSCIP(), SCIP_DECL_READERWRITE(), SCIPwriteLp(), and writeOpbConstraints().

SCIP_RETCODE SCIPsetLinearConsIndicator	(	SCIP *	scip,
		SCIP_CONS *	cons,
		SCIP_CONS *	lincons
	)

sets the linear constraint corresponding to the indicator constraint (may be NULL)

Parameters

scip	SCIP data structure
cons	indicator constraint
lincons	linear constraint

Definition at line 6802 of file cons_indicator.c.

References CONSHDLR_NAME, FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIP_STAGE_PROBLEM, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_IMPLINT, SCIPcaptureCons(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdelCons(), SCIPerrorMessage, SCIPgetNVarsLinear(), SCIPgetStage(), SCIPgetVarsLinear(), SCIPreleaseCons(), SCIPvarGetType(), and TRUE.

SCIP_RETCODE SCIPsetBinaryVarIndicator	(	SCIP *	scip,
		SCIP_CONS *	cons,
		SCIP_VAR *	binvar
	)

sets binary indicator variable for indicator constraint

Parameters

scip	SCIP data structure
cons	indicator constraint
binvar	binary variable to add to the inequality

Definition at line 6890 of file cons_indicator.c.

References CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_ERROR, SCIP_EVENTTYPE_BOUNDCHANGED, SCIP_EVENTTYPE_GBDCHANGED, SCIP_INVALIDCALL, SCIP_OKAY, SCIP_VARTYPE_BINARY, SCIPcatchVarEvent(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconsIsTransformed(), SCIPerrorMessage, SCIPgetTransformedVar(), SCIPvarGetLbLocal(), SCIPvarGetName(), and SCIPvarGetType().

SCIP_VAR* SCIPgetBinaryVarIndicator ( SCIP_CONS * cons )

gets binary variable corresponding to indicator constraint

Parameters

cons	indicator constraint

Definition at line 6873 of file cons_indicator.c.

References CONSHDLR_NAME, NULL, SCIPconsGetData(), SCIPconsGetHdlr(), and SCIPconshdlrGetName().

Referenced by computeRanks(), createCoveringProblem(), createSubSCIP(), getIndCandVars(), SCIP_DECL_CONFLICTEXEC(), SCIP_DECL_READERWRITE(), SCIPwriteGms(), SCIPwriteLp(), and writeOpbConstraints().

SCIP_VAR* SCIPgetSlackVarIndicator ( SCIP_CONS * cons )

gets slack variable corresponding to indicator constraint

Parameters

cons	indicator constraint

Definition at line 6964 of file cons_indicator.c.

References CONSHDLR_NAME, NULL, SCIPconsGetData(), SCIPconsGetHdlr(), and SCIPconshdlrGetName().

Referenced by createSubSCIP(), SCIP_DECL_CONFLICTEXEC(), SCIP_DECL_READERWRITE(), SCIPwriteGms(), SCIPwriteLp(), and writeOpbConstraints().

SCIP_Bool SCIPisViolatedIndicator	(	SCIP *	scip,
		SCIP_CONS *	cons,
		SCIP_SOL *	sol
	)

checks whether indicator constraint is violated w.r.t. sol

Parameters

scip	SCIP data structure
cons	indicator constraint
sol	solution, or NULL to use current node's solution

Definition at line 6981 of file cons_indicator.c.

References FALSE, NULL, SCIPconsGetData(), SCIPconsIsDeleted(), SCIPgetSolVal(), SCIPisFeasPositive(), and TRUE.

Referenced by getIndCandVars().

SCIP_RETCODE SCIPmakeIndicatorFeasible	(	SCIP *	scip,
		SCIP_CONS *	cons,
		SCIP_SOL *	sol,
		SCIP_Bool *	changed
	)

Based on values of other variables, computes slack and binary variable to turn constraint feasible

It will also clean up the solution, i.e., shift slack variable, as follows:

If the inequality is $a^T x + \gamma\, s \leq \beta$ , the value of the slack variable $s$ to achieve equality is

$s^* = \frac{\beta - a^T x^*}{\gamma},$

where $x^*$ is the given solution. In case of $a^T x + \gamma\, s \geq \alpha$ , we arrive at

$s^* = \frac{\alpha - a^T x^*}{\gamma}.$

The typical values of $\gamma$ in the first case is -1 and +1 in the second case.

Now, let $\sigma$ be the sign of $\gamma$ in the first case and $-\gamma$ in the second case. Thus, if $\sigma > 0$ and $s^* < 0$ , the inequality cannot be satisfied by a nonnegative value for the slack variable; in this case, we have to leave the values as they are. If $\sigma < 0$ and $s^* > 0$ , the solution violates the indicator constraint (we can set the slack variable to value $s^*$ ). If $\sigma < 0$ and $s^* \leq 0$ or $\sigma > 0$ and $s^* \geq 0$ , the constraint is satisfied, and we can set the slack variable to 0.

Parameters

scip	SCIP data structure
cons	indicator constraint
sol	solution
changed	pointer to store whether the solution has been changed

Definition at line 7036 of file cons_indicator.c.

References CONSHDLR_NAME, FALSE, NULL, REALABS, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_STAGE_INITPRESOLVE, SCIP_VARSTATUS_FIXED, SCIP_VARSTATUS_NEGATED, SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconshdlrGetName(), SCIPconsIsActive(), SCIPgetLhsLinear(), SCIPgetNVarsLinear(), SCIPgetRhsLinear(), SCIPgetSolVal(), SCIPgetStage(), SCIPgetValsLinear(), SCIPgetVarsLinear(), SCIPisFeasEQ(), SCIPisFeasGE(), SCIPisFeasNegative(), SCIPisFeasPositive(), SCIPisFeasZero(), SCIPisInfinity(), SCIPisZero(), SCIPsetSolVal(), SCIPvarGetLbLocal(), SCIPvarGetNegationVar(), SCIPvarGetNLocksDown(), SCIPvarGetNLocksUp(), SCIPvarGetStatus(), TRUE, and varGetObjDelta().

Referenced by SCIP_DECL_CONSCHECK(), and SCIPmakeIndicatorsFeasible().

SCIP_RETCODE SCIPmakeIndicatorsFeasible	(	SCIP *	scip,
		SCIP_CONSHDLR *	conshdlr,
		SCIP_SOL *	sol,
		SCIP_Bool *	changed
	)

Based on values of other variables, computes slack and binary variable to turn all constraints feasible

Parameters

scip	SCIP data structure
conshdlr	indicator constraint handler
sol	solution
changed	pointer to store whether the solution has been changed

Definition at line 7205 of file cons_indicator.c.

References CONSHDLR_NAME, FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_STAGE_INITPRESOLVE, SCIPconsGetData(), SCIPconshdlrGetConss(), SCIPconshdlrGetName(), SCIPconshdlrGetNConss(), SCIPgetStage(), and SCIPmakeIndicatorFeasible().

Referenced by SCIP_DECL_HEUREXEC().

SCIP_RETCODE SCIPaddLinearConsIndicator	(	SCIP *	scip,
		SCIP_CONSHDLR *	conshdlr,
		SCIP_CONS *	lincons
	)

adds additional linear constraint that is not connected by an indicator constraint, but can be used for separation

adds additional linear constraint that is not connected with an indicator constraint, but can be used for separation

Parameters

scip	SCIP data structure
conshdlr	indicator constraint handler
lincons	linear constraint

Definition at line 7252 of file cons_indicator.c.

References consdataEnsureAddLinConsSize(), CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPconshdlrGetData(), SCIPconshdlrGetName(), and SCIPconsIsLocal().

SCIP_RETCODE SCIPaddRowIndicator	(	SCIP *	scip,
		SCIP_CONSHDLR *	conshdlr,
		SCIP_ROW *	row
	)

adds additional globally valid row that is not connected by an indicator constraint, but can be used for separation

adds additional row that is not connected by an indicator constraint, but can be used for separation

Note: The row is directly added to the alternative polyhedron and is not stored.

Parameters

scip	SCIP data structure
conshdlr	indicator constraint handler
row	row to add

Definition at line 7284 of file cons_indicator.c.

References addAltLPRow(), CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdebugMessage, SCIProwGetName(), and SCIProwIsLocal().

Referenced by SCIP_DECL_CONSINITLP(), and separatePoint().

SCIP

Detailed Description

Functions

Function Documentation