Detailed Description
constraint handler for indicator constraints
An indicator constraint is given by a binary variable \(y\) and an inequality \(ax \leq b\). It states that if \(y = 1\) 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 \(y = 1\).
- Note
- The constraint only implements an implication not an equivalence, i.e., it does not ensure that \(y = 1\) if \(ax \leq b\) or equivalently if \(s = 0\) holds.
This constraint is equivalent to a linear constraint \(ax - s \leq b\) and an SOS1 constraint on \(y\) 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.
Separation Methods
We now explain the handling of indicator constraints in more detail. The indicator constraint handler adds an inequality for each indicator constraint. We assume that this system (with added slack variables) is \( Ax - s \leq b \), where \( x \) are the original variables and \( s \) are the slack variables added by the indicator constraint. Variables \( y \) are the binary variables corresponding to the indicator constraints.
- Note
- In the implementation, we assume that bounds on the original variables \(x\) cannot be influenced by the indicator constraint. If it should be possible to relax these constraints as well, then these constraints have to be added as indicator constraints.
We separate inequalities by using the so-called alternative polyhedron.
Separation via the Alternative Polyhedron
We now describe the separation method of the first method in more detail.
Consider the LP-relaxation of the current subproblem:
\[ \begin{array}{ll} min & c^T x + d^T z\\ & A x - s \leq b, \\ & D x + C z \leq f, \\ & l \leq x \leq u, \\ & u \leq z \leq v, \\ & 0 \leq s. \end{array} \]
As above \(Ax - s \leq b\) contains all inequalities corresponding to indicator constraints, while the system \(Dx + Cy \leq f\) contains all other inequalities (which are ignored in the following). Similarly, variables \(z\) not appearing in indicator constraints are ignored. Bounds for the variables \(x_j\) can be given, in particular, variables can be fixed. Note that \(s \leq 0\) renders the system infeasible.
To generate cuts, we construct the so-called alternative polyhedron:
\[ \begin{array}{ll} P = \{ (w,r,t) : & A^T w - r + t = 0,\\ & b^T w - l^T r + u^T t = -1,\\ & w, r, t \geq 0 \}. \end{array} \]
Here, \(r\) and \(t\) correspond to the lower and upper bounds on \(x\), respectively.
It turns out that the vertices of \(P\) correspond to minimal infeasible subsystems of \(A x \leq b\), \(l \leq x \leq u\). If \(I\) is the index set of such a system, it follows that not all \(s_i\) for \(i \in I\) can be 0, i.e., \(y_i\) can be 1. In other words, the following cut is valid:
\[ \sum_{i \in I} y_i \leq |I| - 1. \]
Separation heuristic
We separate the above inequalities by a heuristic described in
Branch-And-Cut for the Maximum Feasible Subsystem Problem,
Marc Pfetsch, SIAM Journal on Optimization 19, No.1, 21-38 (2008)
The first step in the separation heuristic is to apply the transformation \(\bar{y} = 1 - y\), which transforms the above inequality into the constraint
\[ \sum_{i \in I} \bar{y}_i \geq 1, \]
that is, it is a set covering constraint on the negated variables.
The basic idea is to use the current solution to the LP relaxation and use it as the objective, when optimizing of the alternative polyhedron. Since any vertex corresponds to such an inequality, we can check whether it is violated. To enlarge the chance that we find a violated inequality, we perform a fixing procedure, in which the variable corresponding to an arbitrary element of the last IIS \(I\) is fixed to zero, i.e., cannot be used in the next IISs. This is repeated until the corresponding alternative polyhedron is infeasible, i.e., we have obtained an IIS-cover. For more details see the paper above.
Preprocessing
Since each indicator constraint adds a linear constraint to the formulation, preprocessing of the linear constraints change the above approach as follows.
The system as present in the formulation is the following (ignoring variables that are not contained in indicator constraints and the objective function):
\[ \begin{array}{ll} & A x - s \leq b, \\ & l \leq x \leq u, \\ & s \leq 0. \end{array} \]
Note again that the requirement \(s \leq 0\) leads to an infeasible system. Consider now the preprocessing of the linear constraint (aggregation, bound strengthening, etc.) and assume that this changes the above system to the following:
\[ \begin{array}{ll} & \tilde{A} x - \tilde{B} s \leq \tilde{b}, \\ & \tilde{l} \leq x \leq \tilde{u}, \\ & s \leq 0. \\ \end{array} \]
Note that we forbid multi-aggregation of the \(s\) variables in order to be able to change their bounds in propagation/branching. The corresponding alternative system is the following:
\[ \begin{array}{ll} & \tilde{A}^T w - r + t = 0,\\ & - \tilde{B}^T w + v = 0,\\ & b^T w - l^T r + u^T t = -1,\\ & w, v, r, t \geq 0 \end{array} \qquad \Leftrightarrow \qquad \begin{array}{ll} & \tilde{A}^T w - r + t = 0,\\ & \tilde{B}^T w \geq 0,\\ & b^T w - l^T r + u^T t = -1,\\ & w, r, t \geq 0, \end{array} \]
where the second form arises by substituting \(v \geq 0\). A closer look at this system reveals that it is not larger than the original one:
- (Multi-)Aggregation of variables \(x\) will remove these variables from the formulation, such that the corresponding column of \(\tilde{A}\) (row of \(\tilde{A}^T\)) will be zero.
- The rows of \(\tilde{B}^T\) are not unit vectors, i.e., do not correspond to redundant nonnegativity constraints, only if the corresponding slack variables appear in an aggregation.
Taken together, these two observations yield the conclusion that the new system is roughly as large as the original one.
- Note
- Because of possible (multi-)aggregation it might happen that the linear constraint corresponding to an indicator constraint becomes redundant and is deleted. From this we cannot conclude that the indicator constraint is redundant as well (i.e. always fulfilled), because the corresponding slack variable is still present and its setting to 0 might influence other (linear) constraints. Thus, we have to rely on the dual presolving of the linear constraints to detect this case: If the linear constraint is really redundant, i.e., is always fulfilled, it is deleted and the slack variable can be fixed to 0. In this case, the indicator constraint can be deleted as well.
Definition in file cons_indicator.c.
#include "blockmemshell/memory.h"
#include "lpi/lpi.h"
#include "lpi/type_lpi.h"
#include "scip/expr_var.h"
#include "scip/expr_product.h"
#include "scip/cons_nonlinear.h"
#include "scip/cons_indicator.h"
#include "scip/cons_linear.h"
#include "scip/cons_logicor.h"
#include "scip/cons_varbound.h"
#include "scip/heur_indicator.h"
#include "scip/heur_trysol.h"
#include "scip/pub_conflict.h"
#include "scip/pub_cons.h"
#include "scip/pub_event.h"
#include "scip/pub_lp.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_paramset.h"
#include "scip/pub_var.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_event.h"
#include "scip/scip_general.h"
#include "scip/scip_heur.h"
#include "scip/scip_lp.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_nlp.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_solve.h"
#include "scip/scip_solvingstats.h"
#include "scip/scip_tree.h"
#include "scip/scip_var.h"
#include <string.h>
Go to the source code of this file.
Typedefs | |
typedef enum SCIP_enfosepatype | SCIP_ENFOSEPATYPE |
Enumerations | |
enum | SCIP_enfosepatype { SCIP_TYPE_ENFOLP = 0, SCIP_TYPE_ENFOPS = 1, SCIP_TYPE_ENFORELAX = 2, SCIP_TYPE_SEPALP = 3, SCIP_TYPE_SEPARELAX = 4, SCIP_TYPE_SEPASOL = 5 } |
Macro Definition Documentation
◆ CONSHDLR_NAME
#define CONSHDLR_NAME "indicator" |
Definition at line 240 of file cons_indicator.c.
Referenced by addAltLPConstraint(), addAltLPRow(), addObjcut(), consdataEnsureAddLinConsSize(), deleteAltLPConstraint(), initAlternativeLP(), SCIP_DECL_CONFLICTEXEC(), SCIP_DECL_CONSCHECK(), SCIP_DECL_CONSCOPY(), SCIP_DECL_CONSDELETE(), SCIP_DECL_CONSDISABLE(), SCIP_DECL_CONSENABLE(), SCIP_DECL_CONSENFOLP(), SCIP_DECL_CONSENFOPS(), SCIP_DECL_CONSENFORELAX(), SCIP_DECL_CONSEXIT(), SCIP_DECL_CONSEXITSOL(), SCIP_DECL_CONSFREE(), SCIP_DECL_CONSGETDIVEBDCHGS(), SCIP_DECL_CONSHDLRCOPY(), SCIP_DECL_CONSINIT(), SCIP_DECL_CONSINITLP(), SCIP_DECL_CONSINITPRE(), SCIP_DECL_CONSINITSOL(), SCIP_DECL_CONSLOCK(), SCIP_DECL_CONSPRESOL(), SCIP_DECL_CONSPRINT(), SCIP_DECL_CONSPROP(), SCIP_DECL_CONSRESPROP(), SCIP_DECL_CONSSEPALP(), SCIP_DECL_CONSSEPASOL(), SCIP_DECL_CONSTRANS(), SCIPaddLinearConsIndicator(), SCIPaddRowIndicator(), SCIPaddVarIndicator(), SCIPcreateConsIndicatorGeneric(), SCIPcreateConsIndicatorGenericLinCons(), SCIPgetActiveOnIndicator(), SCIPgetBinaryVarIndicator(), SCIPgetBinaryVarIndicatorGeneric(), SCIPgetLinearConsIndicator(), SCIPgetSlackVarIndicator(), SCIPincludeConshdlrIndicator(), SCIPmakeIndicatorFeasible(), SCIPmakeIndicatorsFeasible(), SCIPsetBinaryVarIndicator(), SCIPsetLinearConsIndicator(), and SCIPsetSlackVarUb().
◆ CONSHDLR_DESC
#define CONSHDLR_DESC "indicator constraint handler" |
Definition at line 241 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_SEPAPRIORITY
#define CONSHDLR_SEPAPRIORITY 10 |
priority of the constraint handler for separation
Definition at line 242 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_ENFOPRIORITY
#define CONSHDLR_ENFOPRIORITY -100 |
priority of the constraint handler for constraint enforcing
Definition at line 243 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_CHECKPRIORITY
#define CONSHDLR_CHECKPRIORITY -6000000 |
priority of the constraint handler for checking feasibility
Definition at line 244 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_SEPAFREQ
#define CONSHDLR_SEPAFREQ 10 |
frequency for separating cuts; zero means to separate only in the root node
Definition at line 245 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_PROPFREQ
#define CONSHDLR_PROPFREQ 1 |
frequency for propagating domains; zero means only preprocessing propagation
Definition at line 246 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_EAGERFREQ
#define CONSHDLR_EAGERFREQ 100 |
frequency for using all instead of only the useful constraints in separation, propagation and enforcement, -1 for no eager evaluations, 0 for first only
Definition at line 247 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_MAXPREROUNDS
#define CONSHDLR_MAXPREROUNDS -1 |
maximal number of presolving rounds the constraint handler participates in (-1: no limit)
Definition at line 250 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_DELAYSEPA
#define CONSHDLR_DELAYSEPA FALSE |
Should separation method be delayed, if other separators found cuts?
Definition at line 251 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_DELAYPROP
#define CONSHDLR_DELAYPROP FALSE |
Should propagation method be delayed, if other propagators found reductions?
Definition at line 252 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_NEEDSCONS
#define CONSHDLR_NEEDSCONS TRUE |
Should the constraint handler be skipped, if no constraints are available?
Definition at line 253 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_PRESOLTIMING
#define CONSHDLR_PRESOLTIMING SCIP_PRESOLTIMING_FAST |
Definition at line 255 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONSHDLR_PROP_TIMING
#define CONSHDLR_PROP_TIMING SCIP_PROPTIMING_BEFORELP |
Definition at line 256 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ EVENTHDLR_BOUND_NAME
#define EVENTHDLR_BOUND_NAME "indicatorbound" |
Definition at line 260 of file cons_indicator.c.
Referenced by SCIP_DECL_EVENTEXEC(), and SCIPincludeConshdlrIndicator().
◆ EVENTHDLR_BOUND_DESC
#define EVENTHDLR_BOUND_DESC "bound change event handler for indicator constraints" |
Definition at line 261 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ EVENTHDLR_RESTART_NAME
#define EVENTHDLR_RESTART_NAME "indicatorrestart" |
Definition at line 263 of file cons_indicator.c.
Referenced by SCIP_DECL_EVENTEXEC(), and SCIPincludeConshdlrIndicator().
◆ EVENTHDLR_RESTART_DESC
#define EVENTHDLR_RESTART_DESC "force restart if absolute gap is 1 or enough binary variables have been fixed" |
Definition at line 264 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONFLICTHDLR_NAME
#define CONFLICTHDLR_NAME "indicatorconflict" |
Definition at line 268 of file cons_indicator.c.
Referenced by SCIP_DECL_CONFLICTEXEC(), SCIP_DECL_CONFLICTFREE(), and SCIPincludeConshdlrIndicator().
◆ CONFLICTHDLR_DESC
#define CONFLICTHDLR_DESC "replace slack variables and generate logicor constraints" |
Definition at line 269 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ CONFLICTHDLR_PRIORITY
#define CONFLICTHDLR_PRIORITY 200000 |
Definition at line 270 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ LINCONSUPGD_PRIORITY
#define LINCONSUPGD_PRIORITY +100000 |
priority of the constraint handler for upgrading of linear constraints
Definition at line 273 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_BRANCHINDICATORS
#define DEFAULT_BRANCHINDICATORS FALSE |
Branch on indicator constraints in enforcing?
Definition at line 276 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_GENLOGICOR
#define DEFAULT_GENLOGICOR FALSE |
Generate logicor constraints instead of cuts?
Definition at line 277 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_ADDCOUPLING
#define DEFAULT_ADDCOUPLING TRUE |
Add coupling constraints or rows if big-M is small enough?
Definition at line 278 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_MAXCOUPLINGVALUE
#define DEFAULT_MAXCOUPLINGVALUE 1e4 |
maximum coefficient for binary variable in coupling constraint
Definition at line 279 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_ADDCOUPLINGCONS
#define DEFAULT_ADDCOUPLINGCONS FALSE |
Add initial variable upper bound constraints, if 'addcoupling' is true?
Definition at line 280 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_SEPACOUPLINGCUTS
#define DEFAULT_SEPACOUPLINGCUTS TRUE |
Should the coupling inequalities be separated dynamically?
Definition at line 281 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_SEPACOUPLINGLOCAL
#define DEFAULT_SEPACOUPLINGLOCAL FALSE |
Allow to use local bounds in order to separate coupling inequalities?
Definition at line 282 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_SEPACOUPLINGVALUE
#define DEFAULT_SEPACOUPLINGVALUE 1e4 |
maximum coefficient for binary variable in separated coupling constraint
Definition at line 283 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_SEPAALTERNATIVELP
#define DEFAULT_SEPAALTERNATIVELP FALSE |
Separate using the alternative LP?
Definition at line 284 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_SEPAPERSPECTIVE
#define DEFAULT_SEPAPERSPECTIVE FALSE |
Separate cuts based on perspective formulation?
Definition at line 285 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_SEPAPERSPLOCAL
#define DEFAULT_SEPAPERSPLOCAL TRUE |
Allow to use local bounds in order to separate perspectice cuts?
Definition at line 286 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_MAXSEPANONVIOLATED
#define DEFAULT_MAXSEPANONVIOLATED 3 |
maximal number of separated non violated IISs, before separation is stopped
Definition at line 287 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_TRYSOLFROMCOVER
#define DEFAULT_TRYSOLFROMCOVER FALSE |
Try to construct a feasible solution from a cover?
Definition at line 288 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_UPGRADELINEAR
#define DEFAULT_UPGRADELINEAR FALSE |
Try to upgrade linear constraints to indicator constraints?
Definition at line 289 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_USEOTHERCONSS
#define DEFAULT_USEOTHERCONSS FALSE |
Collect other constraints to alternative LP?
Definition at line 290 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_USEOBJECTIVECUT
#define DEFAULT_USEOBJECTIVECUT FALSE |
Use objective cut with current best solution to alternative LP?
Definition at line 291 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_UPDATEBOUNDS
#define DEFAULT_UPDATEBOUNDS FALSE |
Update bounds of original variables for separation?
Definition at line 292 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_MAXCONDITIONALTLP
#define DEFAULT_MAXCONDITIONALTLP 0.0 |
max. estimated condition of the solution basis matrix of the alt. LP to be trustworthy (0.0 to disable check)
Definition at line 293 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_MAXSEPACUTS
#define DEFAULT_MAXSEPACUTS 100 |
maximal number of cuts separated per separation round
Definition at line 294 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_MAXSEPACUTSROOT
#define DEFAULT_MAXSEPACUTSROOT 2000 |
maximal number of cuts separated per separation round in the root node
Definition at line 295 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_REMOVEINDICATORS
#define DEFAULT_REMOVEINDICATORS FALSE |
Remove indicator constraint if corresponding variable bound constraint has been added?
Definition at line 296 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_GENERATEBILINEAR
#define DEFAULT_GENERATEBILINEAR FALSE |
Do not generate indicator constraint, but a bilinear constraint instead?
Definition at line 297 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_SCALESLACKVAR
#define DEFAULT_SCALESLACKVAR FALSE |
Scale slack variable coefficient at construction time?
Definition at line 298 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_NOLINCONSCONT
#define DEFAULT_NOLINCONSCONT FALSE |
Decompose problem (do not generate linear constraint if all variables are continuous)?
Definition at line 299 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_TRYSOLUTIONS
#define DEFAULT_TRYSOLUTIONS TRUE |
Try to make solutions feasible by setting indicator variables?
Definition at line 300 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_ENFORCECUTS
#define DEFAULT_ENFORCECUTS FALSE |
In enforcing try to generate cuts (only if sepaalternativelp is true)?
Definition at line 301 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_DUALREDUCTIONS
#define DEFAULT_DUALREDUCTIONS TRUE |
Should dual reduction steps be performed?
Definition at line 302 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_ADDOPPOSITE
#define DEFAULT_ADDOPPOSITE FALSE |
Add opposite inequality in nodes in which the binary variable has been fixed to 0?
Definition at line 303 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_CONFLICTSUPGRADE
#define DEFAULT_CONFLICTSUPGRADE FALSE |
Try to upgrade bounddisjunction conflicts by replacing slack variables?
Definition at line 304 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_FORCERESTART
#define DEFAULT_FORCERESTART FALSE |
Force restart if absolute gap is 1 or enough binary variables have been fixed?
Definition at line 305 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ DEFAULT_RESTARTFRAC
#define DEFAULT_RESTARTFRAC 0.9 |
fraction of binary variables that need to be fixed before restart occurs (in forcerestart)
Definition at line 306 of file cons_indicator.c.
Referenced by SCIPincludeConshdlrIndicator().
◆ OBJEPSILON
#define OBJEPSILON 0.001 |
value to add to objective in alt. LP if the binary variable is 1 to get small IISs
Definition at line 310 of file cons_indicator.c.
Referenced by setAltLPObj(), and setAltLPObjZero().
◆ SEPAALTTHRESHOLD
#define SEPAALTTHRESHOLD 10 |
only separate IIS cuts if the number of separated coupling cuts is less than this value
Definition at line 311 of file cons_indicator.c.
Referenced by separateIndicators().
◆ MAXROUNDINGROUNDS
#define MAXROUNDINGROUNDS 1 |
maximal number of rounds that produced cuts in separation
Definition at line 312 of file cons_indicator.c.
Referenced by initConshdlrData().
◆ SCIP_CALL_PARAM
#define SCIP_CALL_PARAM | ( | x | ) |
Definition at line 429 of file cons_indicator.c.
Referenced by checkAltLPInfeasible(), extendToCover(), initAlternativeLP(), and SCIP_DECL_CONSCHECK().
Typedef Documentation
◆ SCIP_ENFOSEPATYPE
typedef enum SCIP_enfosepatype SCIP_ENFOSEPATYPE |
Definition at line 425 of file cons_indicator.c.
Enumeration Type Documentation
◆ SCIP_enfosepatype
enum SCIP_enfosepatype |
type of enforcing/separation call
Definition at line 416 of file cons_indicator.c.
Function Documentation
◆ SCIP_DECL_EVENTEXEC() [1/2]
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static |
execute the event handler for getting variable bound changes
We update the number of variables fixed to be nonzero.
Definition at line 449 of file cons_indicator.c.
References EVENTHDLR_BOUND_NAME, NULL, SCIP_EVENTTYPE_LBRELAXED, SCIP_EVENTTYPE_LBTIGHTENED, SCIP_EVENTTYPE_UBRELAXED, SCIP_EVENTTYPE_UBTIGHTENED, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_Real, SCIPABORT, SCIPdebugMsg, SCIPerrorMessage, SCIPeventGetNewbound(), SCIPeventGetOldbound(), SCIPeventGetType(), SCIPeventGetVar(), SCIPeventhdlrGetName(), SCIPisFeasNegative(), SCIPisFeasPositive(), and SCIPvarGetName().
◆ SCIP_DECL_EVENTEXEC() [2/2]
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static |
exec the event handler for forcing a restart
There are two cases in which we perform a (user) restart:
- If we have a max FS instance, i.e., the objective is 1 for indicator variables and 0 otherwise, we can force a restart if the gap is 1. In this case, the remaining work consists of proving infeasibility of the non-fixed indicators.
- If a large fraction of the binary indicator variables have been globally fixed, it makes sense to force a restart.
Definition at line 533 of file cons_indicator.c.
References EVENTHDLR_RESTART_NAME, NULL, REALABS, SCIP_CALL, SCIP_DECL_CONFLICTFREE(), SCIP_EVENTTYPE_BESTSOLFOUND, SCIP_EVENTTYPE_GLBCHANGED, SCIP_EVENTTYPE_GUBCHANGED, SCIP_INVALIDDATA, SCIP_OKAY, SCIP_Real, SCIP_STAGE_SOLVING, SCIP_VARTYPE_BINARY, SCIP_VERBLEVEL_NORMAL, SCIPABORT, SCIPdebugMsg, SCIPdropEvent(), SCIPerrorMessage, SCIPeventGetNewbound(), SCIPeventGetOldbound(), SCIPeventGetType(), SCIPeventGetVar(), SCIPeventhdlrGetName(), SCIPfindBranchrule(), SCIPgetDualbound(), SCIPgetPrimalbound(), SCIPgetStage(), SCIPisEQ(), SCIPisGE(), SCIPisIntegral(), SCIPisParamFixed(), SCIPisZero(), SCIPrestartSolve(), SCIPsetIntParam(), SCIPvarGetName(), SCIPvarGetType(), SCIPverbMessage(), and TRUE.
◆ SCIP_DECL_CONFLICTFREE()
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static |
destructor of conflict handler to free conflict handler data (called when SCIP is exiting)
Definition at line 639 of file cons_indicator.c.
References CONFLICTHDLR_NAME, NULL, SCIP_DECL_CONFLICTEXEC(), SCIP_OKAY, SCIPconflicthdlrGetData(), SCIPconflicthdlrGetName(), and SCIPfreeBlockMemory.
Referenced by SCIP_DECL_EVENTEXEC().
◆ SCIP_DECL_CONFLICTEXEC()
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static |
conflict processing method of conflict handler (called when conflict was found)
In this conflict handler we try to replace slack variables by binary indicator variables and generate a logicor constraint if possible.
Definition at line 662 of file cons_indicator.c.
References checkTransferBoolParam(), CONFLICTHDLR_NAME, CONSHDLR_NAME, FALSE, NULL, SCIP_Bool, SCIP_BOUNDTYPE_LOWER, SCIP_CALL, SCIP_CONSADDED, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_IMPLINT, SCIPaddConflict(), SCIPallocBufferArray, SCIPbdchginfoGetBoundtype(), SCIPbdchginfoGetNewbound(), SCIPbdchginfoGetVar(), SCIPboundtypeOpposite(), SCIPconflicthdlrGetData(), SCIPconflicthdlrGetName(), SCIPconshdlrGetConss(), SCIPconshdlrGetName(), SCIPconshdlrGetNConss(), SCIPcreateConsLogicor(), SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetBinaryVarIndicator(), SCIPgetNConflictConssApplied(), SCIPgetNegatedVar(), SCIPgetNRuns(), SCIPgetSlackVarIndicator(), SCIPinfoMessage(), SCIPisFeasZero(), SCIPprintCons(), SCIPsnprintf(), SCIPvarGetName(), SCIPvarGetType(), SCIPvarIsBinary(), and TRUE.
Referenced by SCIP_DECL_CONFLICTFREE().
◆ checkTransferBoolParam()
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static |
check whether we transfer a changed parameter to the given value
- See also
- paramChangedIndicator()
- Parameters
-
scip SCIP data structure param parameter name parameter name to check newvalue new value value old and possibly changed value of parameter
Definition at line 832 of file cons_indicator.c.
References NULL, paramname, SCIP_CALL, SCIP_DECL_PARAMCHGD(), SCIP_OKAY, SCIP_PARAMTYPE_BOOL, SCIP_STAGE_PROBLEM, SCIPchgBoolParam(), SCIPgetStage(), SCIPparamGetName(), SCIPparamGetType(), and SCIPwarningMessage().
Referenced by SCIP_DECL_CONFLICTEXEC(), and SCIP_DECL_PARAMCHGD().
◆ SCIP_DECL_PARAMCHGD()
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static |
called after a parameter has been changed
Definition at line 879 of file cons_indicator.c.
References checkTransferBoolParam(), NULL, SCIP_CALL, SCIP_ERROR, SCIP_MAXSTRLEN, SCIP_OBJSEN_MINIMIZE, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_AGGREGATED, SCIP_VARSTATUS_MULTAGGR, SCIPABORT, SCIPallocBufferArray, SCIPblkmem(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetConss(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconshdlrGetNConss(), SCIPconsIsActive(), SCIPconsIsEnabled(), SCIPconsIsLocal(), SCIPdebugMsg, SCIPerrorMessage, SCIPfindConshdlr(), SCIPfreeBufferArray, SCIPgetConss(), SCIPgetLhsLinear(), SCIPgetMessagehdlr(), SCIPgetNConss(), SCIPgetNVars(), SCIPgetNVarsLinear(), SCIPgetProbvarSum(), SCIPgetRhsLinear(), SCIPgetValsLinear(), SCIPgetVarsLinear(), SCIPhashmapCreate(), SCIPhashmapExists(), SCIPhashmapFree(), SCIPhashmapGetImageInt(), SCIPhashmapInsertInt(), SCIPinfinity(), SCIPisFeasZero(), SCIPisInfinity(), SCIPisZero(), SCIPlpiAddCols(), SCIPlpiAddRows(), SCIPlpiCreate(), SCIPlpiFree(), SCIPlpiInfinity(), SCIPlpiIsPrimalInfeasible(), SCIPlpiSolvePrimal(), SCIPlpiWriteLP(), SCIPsnprintf(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetStatus(), SCIPvarGetUbLocal(), and varGetObjDelta().
Referenced by checkTransferBoolParam().
◆ varGetObjDelta()
return objective contribution of variable
Special treatment of negated variables: return negative of objective of original variable. SCIPvarGetObj() would return 0 in these cases.
- Parameters
-
var variable
Definition at line 1294 of file cons_indicator.c.
References consdataEnsureAddLinConsSize(), NULL, SCIP_VARSTATUS_AGGREGATED, SCIPvarGetAggrScalar(), SCIPvarGetAggrVar(), SCIPvarGetNegatedVar(), SCIPvarGetObj(), SCIPvarGetStatus(), SCIPvarIsBinary(), and SCIPvarIsNegated().
Referenced by enforceCuts(), extendToCover(), presolRoundIndicator(), propIndicator(), SCIP_DECL_CONSINITSOL(), SCIP_DECL_PARAMCHGD(), SCIPmakeIndicatorFeasible(), and separateIISRounding().
◆ consdataEnsureAddLinConsSize()
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static |
ensures that the addlincons array can store at least num entries
- Parameters
-
scip SCIP data structure conshdlr constraint handler num minimum number of entries to store
Definition at line 1315 of file cons_indicator.c.
References CONSHDLR_NAME, initAlternativeLP(), NULL, SCIP_CALL, SCIP_OKAY, SCIPcalcMemGrowSize(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), and SCIPreallocBlockMemoryArray.
Referenced by SCIPaddLinearConsIndicator(), and varGetObjDelta().
◆ initAlternativeLP()
|
static |
initialize alternative LP
The alternative system is organized as follows:
- The first row corresponds to the right hand side of the original system.
- The next nconss constraints correspond to the slack variables.
- The rows after that correspond to the original variables.
- Parameters
-
scip SCIP pointer conshdlr constraint handler
Definition at line 1355 of file cons_indicator.c.
References checkLPBoundsClean(), CONSHDLR_NAME, FALSE, NULL, SCIP_CALL, SCIP_CALL_PARAM, SCIP_LPPAR_FASTMIP, SCIP_LPPAR_FROMSCRATCH, SCIP_LPPAR_PRESOLVING, SCIP_LPPAR_SCALING, SCIP_OBJSEN_MINIMIZE, SCIP_OKAY, SCIP_Real, SCIPblkmem(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdebugMsg, SCIPgetMessagehdlr(), SCIPgetNVars(), SCIPhashmapCreate(), SCIPlpiAddRows(), SCIPlpiCreate(), SCIPlpiSetIntpar(), and TRUE.
Referenced by addAltLPColumn(), and consdataEnsureAddLinConsSize().
◆ checkLPBoundsClean()
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static |
check whether the bounds in given (alternative) LP are set correctly (for debugging)
- Parameters
-
scip SCIP pointer lp LP for which bounds should be checked nconss number of constraints conss constraints
Definition at line 1405 of file cons_indicator.c.
References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPABORT, SCIPallocBufferArray, SCIPconsGetData(), SCIPfreeBufferArray, SCIPisFeasZero(), SCIPlpiGetBounds(), SCIPlpiGetNCols(), SCIPlpiIsInfinity(), setAltLPObj(), and TRUE.
Referenced by enforceCuts(), initAlternativeLP(), SCIP_DECL_CONSCHECK(), and separateIISRounding().
◆ setAltLPObj()
|
static |
set the alternative system objective function
We assume that the objective function coefficients of the variables other than the binary indicators are always 0 and hence do not have to be changed.
We already use the tranformation \(y' = 1 - y\).
- Parameters
-
scip SCIP pointer lp alternative LP sol solution to be dealt with nconss number of constraints conss indicator constraints
Definition at line 1483 of file cons_indicator.c.
References NULL, OBJEPSILON, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconsGetData(), SCIPfreeBufferArray, SCIPgetSolVal(), SCIPisFeasEQ(), SCIPlpiChgObj(), and setAltLPObjZero().
Referenced by checkLPBoundsClean(), and separateIISRounding().
◆ setAltLPObjZero()
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static |
set the alternative system objective function to some small value
- Parameters
-
scip SCIP pointer lp alternative LP nconss number of constraints conss indicator constraints
Definition at line 1536 of file cons_indicator.c.
References fixAltLPVariables(), NULL, OBJEPSILON, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconsGetData(), SCIPfreeBufferArray, and SCIPlpiChgObj().
Referenced by enforceCuts(), SCIP_DECL_CONSCHECK(), and setAltLPObj().
◆ fixAltLPVariables()
|
static |
fix variable given by S to 0
- Parameters
-
scip SCIP pointer lp alternative LP nconss number of constraints conss indicator constraints S bitset of variables
Definition at line 1584 of file cons_indicator.c.
References fixAltLPVariable(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconsGetData(), SCIPfreeBufferArray, and SCIPlpiChgBounds().
Referenced by enforceCuts(), SCIP_DECL_CONSCHECK(), separateIISRounding(), and setAltLPObjZero().
◆ fixAltLPVariable()
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static |
fix variable ind to 0
- Parameters
-
lp alternative LP ind variable that should be fixed to 0
Definition at line 1643 of file cons_indicator.c.
References SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPlpiChgBounds(), and unfixAltLPVariable().
Referenced by deleteAltLPConstraint(), extendToCover(), fixAltLPVariables(), and SCIP_DECL_CONSDISABLE().
◆ unfixAltLPVariable()
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static |
unfix variable ind to 0
- Parameters
-
lp alternative LP ind variable that should be fixed to 0
Definition at line 1660 of file cons_indicator.c.
References SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPlpiChgBounds(), SCIPlpiInfinity(), and unfixAltLPVariables().
Referenced by fixAltLPVariable(), and SCIP_DECL_CONSENABLE().
◆ unfixAltLPVariables()
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static |
unfix variable given by S to 0
- Parameters
-
scip SCIP pointer lp alternative LP nconss number of constraints conss indicator constraints S bitset of variables
Definition at line 1676 of file cons_indicator.c.
References NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconsGetData(), SCIPfreeBufferArray, SCIPlpiChgBounds(), SCIPlpiInfinity(), and updateFirstRow().
Referenced by enforceCuts(), SCIP_DECL_CONSCHECK(), separateIISRounding(), and unfixAltLPVariable().
◆ updateFirstRow()
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static |
update bounds in first row to the current ones
- Parameters
-
scip SCIP pointer conshdlrdata constraint handler
Definition at line 1735 of file cons_indicator.c.
References FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPdebugMsg, SCIPgetNVars(), SCIPgetVars(), SCIPhashmapExists(), SCIPhashmapGetImageInt(), SCIPisEQ(), SCIPlpiChgCoef(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), and updateFirstRowGlobal().
Referenced by separateIISRounding(), and unfixAltLPVariables().
◆ updateFirstRowGlobal()
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static |
update bounds in first row to the global bounds
- Parameters
-
scip SCIP pointer conshdlrdata constraint handler
Definition at line 1799 of file cons_indicator.c.
References checkIISlocal(), NULL, SCIP_CALL, SCIP_OKAY, SCIPdebugMsg, SCIPgetNVars(), SCIPgetVars(), SCIPhashmapExists(), SCIPhashmapGetImageInt(), SCIPlpiChgCoef(), SCIPvarGetLbGlobal(), and SCIPvarGetUbGlobal().
Referenced by enforceCuts(), SCIP_DECL_CONSCHECK(), and updateFirstRow().
◆ checkIISlocal()
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static |
check whether IIS defined by vector corresponds to a local cut
- Parameters
-
scip SCIP pointer conshdlrdata constraint handler vector solution to alternative LP defining IIS isLocal whether the IIS uses local bounds different from the global ones
Definition at line 1860 of file cons_indicator.c.
References FALSE, NULL, scaleFirstRow(), SCIP_CALL, SCIP_OKAY, SCIPgetNVars(), SCIPgetVars(), SCIPhashmapExists(), SCIPhashmapGetImageInt(), SCIPisEQ(), SCIPisFeasZero(), SCIPlpiGetNCols(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), and TRUE.
Referenced by extendToCover(), and updateFirstRowGlobal().
◆ scaleFirstRow()
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static |
compute scaling for first row
If the coefficients in the first row are large, a right hand side of -1 might not be adequate. Here, we replace the right hand side by the sum of the coefficients divided by the number of nonzeros.
- Parameters
-
scip SCIP pointer conshdlrdata constraint handler
Definition at line 1949 of file cons_indicator.c.
References addAltLPColumn(), NULL, REALABS, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPfreeBufferArray, SCIPlpiChgSides(), SCIPlpiGetNCols(), SCIPlpiGetRows(), and TRUE.
Referenced by checkIISlocal(), enforceCuts(), SCIP_DECL_CONSCHECK(), and separateIISRounding().
◆ addAltLPColumn()
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static |
add column to alternative LP
See the description at the top of the file for more information.
- Parameters
-
scip SCIP pointer conshdlr constraint handler conshdlrdata data of constraint handler slackvar slack variable or NULL nvars number of variables in column vars variables for column vals values for column rhscoef coefficient for first row objcoef objective in alternative LP sign sign (+1,-1) for column colfree whether column should be free, e.g., for equations colindex index of new column (return value)
Definition at line 2002 of file cons_indicator.c.
References addAltLPConstraint(), FALSE, initAlternativeLP(), NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPdebugMsg, SCIPfreeBufferArray, SCIPhashmapExists(), SCIPhashmapGetImageInt(), SCIPhashmapInsertInt(), SCIPhashmapSetImageInt(), SCIPisEQ(), SCIPisFeasZero(), SCIPisInfinity(), SCIPisZero(), SCIPlpiAddCols(), SCIPlpiAddRows(), SCIPlpiGetNCols(), SCIPlpiGetNRows(), SCIPlpiInfinity(), SCIPlpiWriteLP(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetUbGlobal(), and TRUE.
Referenced by addAltLPConstraint(), addAltLPRow(), addObjcut(), and scaleFirstRow().
◆ addAltLPConstraint()
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static |
add column corresponding to constraint to alternative LP
See the description at the top of the file for more information.
- Parameters
-
scip SCIP pointer conshdlr constraint handler lincons linear constraint slackvar slack variable or NULL objcoef objective coefficient colindex index of new column
Definition at line 2274 of file cons_indicator.c.
References addAltLPColumn(), addAltLPRow(), CONSHDLR_NAME, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_AGGREGATED, SCIP_VARSTATUS_MULTAGGR, SCIPallocBufferArray, SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconsIsActive(), SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetLhsLinear(), SCIPgetNVarsLinear(), SCIPgetProbvarSum(), SCIPgetRhsLinear(), SCIPgetValsLinear(), SCIPgetVarsLinear(), SCIPinfinity(), SCIPisEQ(), SCIPisInfinity(), SCIPisZero(), SCIPvarGetStatus(), and TRUE.
Referenced by addAltLPColumn(), consdataCreate(), and SCIP_DECL_CONSINITSOL().
◆ addAltLPRow()
|
static |
add column corresponding to row to alternative LP
See the description at the top of the file for more information.
- Parameters
-
scip SCIP pointer conshdlr constraint handler row row to add objcoef objective coefficient colindex index of new column
Definition at line 2375 of file cons_indicator.c.
References addAltLPColumn(), addObjcut(), CONSHDLR_NAME, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPcolGetVar(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPfreeBufferArray, SCIPisEQ(), SCIPisInfinity(), SCIProwGetCols(), SCIProwGetConstant(), SCIProwGetLhs(), SCIProwGetNNonz(), SCIProwGetRhs(), SCIProwGetVals(), SCIProwIsLocal(), and TRUE.
Referenced by addAltLPConstraint(), and SCIPaddRowIndicator().
◆ addObjcut()
|
static |
try to add objective cut as column to alternative LP
- Parameters
-
scip SCIP pointer conshdlr constraint handler
Definition at line 2448 of file cons_indicator.c.
References addAltLPColumn(), CONSHDLR_NAME, deleteAltLPConstraint(), FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetVarsData(), SCIPisInfinity(), SCIPisZero(), and SCIPvarGetObj().
Referenced by addAltLPRow(), and updateObjUpperbound().
◆ deleteAltLPConstraint()
|
static |
delete column corresponding to constraint in alternative LP
We currently just fix the corresponding variable to 0.
- Parameters
-
scip SCIP pointer conshdlr constraint handler cons indicator constraint
Definition at line 2518 of file cons_indicator.c.
References CONSHDLR_NAME, FALSE, fixAltLPVariable(), NULL, SCIP_CALL, SCIP_OKAY, SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdebugMsg, and updateObjUpperbound().
Referenced by addObjcut(), and SCIP_DECL_CONSDELETE().
◆ updateObjUpperbound()
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static |
update upper bound in alternative LP
- Parameters
-
scip SCIP pointer conshdlr constraint handler conshdlrdata constraint handler data
Definition at line 2557 of file cons_indicator.c.
References addObjcut(), checkAltLPInfeasible(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPcutoffbounddelta(), SCIPdebugMsg, SCIPfeasCeil(), SCIPgetUpperbound(), SCIPisEQ(), SCIPisInfinity(), SCIPisLT(), SCIPisObjIntegral(), SCIPlpiChgCoef(), SCIPlpiGetCoef(), and SCIPlpiWriteLP().
Referenced by deleteAltLPConstraint(), enforceCuts(), and separateIISRounding().
◆ checkAltLPInfeasible()
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static |
check whether the given LP is infeasible
If primal is false we assume that the problem is dual feasible, e.g., the problem was only changed by fixing bounds!
This is the workhorse for all methods that have to solve the alternative LP. We try in several ways to recover from possible stability problems.
- Precondition
- It is assumed that all parameters for the alternative LP are set.
- Parameters
-
scip SCIP pointer lp LP maxcondition maximal allowed condition of LP solution basis matrix primal whether we are using the primal or dual simplex infeasible output: whether the LP is infeasible error output: whether an error occurred
Definition at line 2633 of file cons_indicator.c.
References extendToCover(), FALSE, NULL, SCIP_CALL, SCIP_CALL_PARAM, SCIP_INVALID, SCIP_LPERROR, SCIP_LPPAR_FROMSCRATCH, SCIP_LPPAR_PRESOLVING, SCIP_LPPAR_SCALING, SCIP_LPSOLQUALITY_ESTIMCONDITION, SCIP_OKAY, SCIP_Real, SCIPdebugMsg, SCIPlpiExistsPrimalRay(), SCIPlpiGetInternalStatus(), SCIPlpiGetRealSolQuality(), SCIPlpiIsOptimal(), SCIPlpiIsPrimalInfeasible(), SCIPlpiIsPrimalUnbounded(), SCIPlpiIsStable(), SCIPlpiSetIntpar(), SCIPlpiSolveDual(), SCIPlpiSolvePrimal(), SCIPwarningMessage(), and TRUE.
Referenced by extendToCover(), SCIP_DECL_CONSCHECK(), and updateObjUpperbound().
◆ extendToCover()
|
static |
tries to extend a given set of variables to a cover
At each step we include a variable which covers a new IIS. The corresponding IIS inequalities are added to the LP, if this not already happened.
- Precondition
- It is assumed that all parameters for the alternative LP are set and that the variables corresponding to S are fixed. Furthermore
xVal_
should contain the current LP solution.
- Parameters
-
scip SCIP pointer conshdlr constraint handler conshdlrdata constraint handler data lp LP sol solution to be separated enfosepatype type of enforcing/separating type removable whether cuts should be removable genlogicor should logicor constraints be generated? nconss number of constraints conss indicator constraints S bitset of variables size size of S value objective value of S error output: whether an error occurred cutoff whether we detected a cutoff by an infeasible inequality nGen number of generated cuts
Definition at line 2780 of file cons_indicator.c.
References checkAltLPInfeasible(), checkIISlocal(), consdataCreate(), FALSE, fixAltLPVariable(), NULL, SCIP_Bool, SCIP_CALL, SCIP_CALL_PARAM, SCIP_LPPAR_FROMSCRATCH, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_PLUGINNOTFOUND, SCIP_Real, SCIP_TYPE_ENFOLP, SCIP_TYPE_ENFOPS, SCIP_TYPE_ENFORELAX, SCIP_TYPE_SEPALP, SCIP_TYPE_SEPARELAX, SCIP_TYPE_SEPASOL, SCIPABORT, SCIPaddCons(), SCIPaddPoolCut(), SCIPaddRow(), SCIPaddVarToRow(), SCIPallocBufferArray, SCIPcacheRowExtensions(), SCIPconsGetData(), SCIPcreateConsLogicor(), SCIPcreateEmptyRowConshdlr(), SCIPdebugMsg, SCIPenfolpCons(), SCIPenfopsCons(), SCIPenforelaxCons(), SCIPerrorMessage, SCIPfindHeur(), SCIPflushRowExtensions(), SCIPfreeBufferArray, SCIPgetNBinVars(), SCIPgetNegatedVar(), SCIPgetNIntVars(), SCIPgetRowSolFeasibility(), SCIPgetSolVal(), SCIPheurPassIndicator(), SCIPinfinity(), SCIPinfoMessage(), SCIPisEfficacious(), SCIPisFeasNegative(), SCIPisFeasZero(), SCIPlpiGetNCols(), SCIPlpiGetSol(), SCIPlpiSetIntpar(), SCIPprintCons(), SCIPprintRow(), SCIPreleaseCons(), SCIPreleaseRow(), SCIPsepalpCons(), SCIPsepasolCons(), SCIPsnprintf(), TRUE, and varGetObjDelta().
Referenced by checkAltLPInfeasible(), enforceCuts(), and separateIISRounding().
◆ consdataCreate()
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static |
creates and initializes consdata
- Parameters
-
scip SCIP data structure conshdlr constraint handler conshdlrdata constraint handler data consname name of constraint (or NULL) consdata pointer to linear constraint data eventhdlrbound event handler for bound change events eventhdlrrestart event handler for handling restarts binvar binary variable (or NULL) activeone whether the constraint is active on 1 or not lessthanineq whether the original linear constraint is a less-than-rhs (TRUE) or not slackvar slack variable lincons linear constraint (or NULL) linconsactive whether the linear constraint is active
Definition at line 3133 of file cons_indicator.c.
References addAltLPConstraint(), createVarUbs(), FALSE, NULL, SCIP_CALL, SCIP_ERROR, SCIP_EVENTTYPE_BOUNDCHANGED, SCIP_EVENTTYPE_GBDCHANGED, SCIP_OKAY, SCIP_STAGE_INITSOLVE, SCIP_VARTYPE_BINARY, SCIPallocBlockMemory(), SCIPcatchVarEvent(), SCIPdebugMsg, SCIPerrorMessage, SCIPgetNegatedVar(), SCIPgetStage(), SCIPgetTransformedVar(), SCIPinfoMessage(), SCIPisFeasPositive(), SCIPisTransformed(), SCIPmarkDoNotMultaggrVar(), SCIPprintCons(), SCIPvarGetLbLocal(), SCIPvarGetName(), and SCIPvarGetType().
Referenced by extendToCover(), SCIP_DECL_CONSTRANS(), SCIPcreateConsIndicatorGeneric(), and SCIPcreateConsIndicatorGenericLinCons().
◆ createVarUbs()
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static |
create variable upper bounds for constraints
- Parameters
-
scip SCIP pointer conshdlrdata constraint handler data conss constraints nconss number of constraints ngen number of successful operations
Definition at line 3268 of file cons_indicator.c.
References FALSE, NULL, presolRoundIndicator(), SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPaddCons(), SCIPconsAddUpgradeLocks(), SCIPconsGetData(), SCIPconsGetName(), SCIPconsGetNUpgradeLocks(), SCIPconsIsActive(), SCIPconsIsModifiable(), SCIPcreateConsVarbound(), SCIPdebugMsg, SCIPdelCons(), SCIPinfinity(), SCIPisNegative(), SCIPreleaseCons(), SCIPsnprintf(), SCIPvarGetUbGlobal(), and TRUE.
Referenced by consdataCreate(), and SCIP_DECL_CONSPRESOL().
◆ presolRoundIndicator()
|
static |
perform one presolving round
- Parameters
-
scip SCIP pointer conshdlrdata constraint handler data cons constraint consdata constraint data dualreductions should dual reductions be performed? cutoff whether a cutoff happened success whether we performed a successful reduction ndelconss number of deleted constraints nfixedvars number of fixed variables
Definition at line 3348 of file cons_indicator.c.
References bound, FALSE, NULL, propIndicator(), SCIP_Bool, SCIP_BOUNDTYPE_LOWER, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_EVENTTYPE_BOUNDCHANGED, SCIP_EVENTTYPE_GBDCHANGED, SCIP_LOCKTYPE_MODEL, SCIP_OKAY, SCIP_Real, SCIP_VARSTATUS_AGGREGATED, SCIP_VARSTATUS_NEGATED, SCIPaddVarLocksType(), SCIPcaptureVar(), SCIPcatchVarEvent(), SCIPconsAddUpgradeLocks(), SCIPconsGetName(), SCIPconsGetNUpgradeLocks(), SCIPconsIsActive(), SCIPconsIsModifiable(), SCIPdebugMsg, SCIPdelCons(), SCIPdropVarEvent(), SCIPfixVar(), SCIPisEQ(), SCIPisFeasPositive(), SCIPisFeasZero(), SCIPlockVarCons(), SCIPreleaseVar(), SCIPunlockVarCons(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetNegatedVar(), SCIPvarGetNLocksDownType(), SCIPvarGetNLocksUpType(), SCIPvarGetProbvarBinary(), SCIPvarGetProbvarBound(), SCIPvarGetStatus(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), SCIPvarIsActive(), SCIPvarIsNegated(), TRUE, and varGetObjDelta().
Referenced by createVarUbs(), and SCIP_DECL_CONSPRESOL().
◆ propIndicator()
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static |
propagate indicator constraint
- Parameters
-
scip SCIP pointer cons constraint consdata constraint data dualreductions should dual reductions be performed? addopposite add opposite inequalities if binary var = 0? cutoff whether a cutoff happened nGen number of domain changes
Definition at line 3681 of file cons_indicator.c.
References enforceCuts(), FALSE, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_CONFTYPE_PROPAGATION, SCIP_LOCKTYPE_MODEL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_Real, SCIP_STAGE_PRESOLVING, SCIP_STAGE_SOLVING, SCIP_VARSTATUS_MULTAGGR, SCIPaddConflictBinvar(), SCIPaddConflictLb(), SCIPaddCons(), SCIPallocBufferArray, SCIPanalyzeConflictCons(), SCIPconsAddUpgradeLocks(), SCIPconsGetName(), SCIPconsGetNUpgradeLocks(), SCIPconsIsActive(), SCIPconsIsModifiable(), SCIPcreateConsLinear(), SCIPdebugMsg, SCIPdebugPrintCons, SCIPdelConsLocal(), SCIPfreeBufferArray, SCIPgetLhsLinear(), SCIPgetNVarsLinear(), SCIPgetRhsLinear(), SCIPgetStage(), SCIPgetValsLinear(), SCIPgetVarsLinear(), SCIPincConsAge(), SCIPinferVarLbCons(), SCIPinferVarUbCons(), SCIPinfinity(), SCIPinitConflictAnalysis(), SCIPinProbing(), SCIPinRepropagation(), SCIPisConflictAnalysisApplicable(), SCIPisEQ(), SCIPisFeasGE(), SCIPisFeasPositive(), SCIPisFeasZero(), SCIPisInfinity(), SCIPisIntegral(), SCIPisPositive(), SCIPisZero(), SCIPreleaseCons(), SCIPresetConsAge(), SCIPsnprintf(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetNLocksDownType(), SCIPvarGetNLocksUpType(), SCIPvarGetStatus(), SCIPvarGetUbLocal(), SCIPvarIsIntegral(), TRUE, and varGetObjDelta().
Referenced by enforceIndicators(), presolRoundIndicator(), and SCIP_DECL_CONSPROP().
◆ enforceCuts()
|
static |
enforcement method that produces cuts if possible
This is a variant of the enforcement method that generates cuts/constraints via the alternative LP, if possible.
- Parameters
-
scip SCIP pointer conshdlr constraint handler nconss number of constraints conss indicator constraints sol solution to be enforced enfosepatype type of enforcing/separating type genlogicor whether logicor constraint should be generated cutoff whether we detected a cutoff by an infeasible inequality nGen number of cuts generated
Definition at line 3981 of file cons_indicator.c.
References checkLPBoundsClean(), enforceIndicators(), extendToCover(), FALSE, fixAltLPVariables(), NULL, scaleFirstRow(), SCIP_Bool, SCIP_CALL, SCIP_LPERROR, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconsGetData(), SCIPconshdlrGetData(), SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetSolVal(), SCIPisFeasIntegral(), SCIPisFeasZero(), setAltLPObjZero(), TRUE, unfixAltLPVariables(), updateFirstRowGlobal(), updateObjUpperbound(), and varGetObjDelta().
Referenced by enforceIndicators(), and propIndicator().
◆ enforceIndicators()
|
static |
enforcement method
We check whether the current solution is feasible, i.e., if binvar = 1 implies that slackvar = 0. If not, we branch as follows:
In one branch we fix binvar = 1 and slackvar = 0. In the other branch we fix binvar = 0 and leave slackvar unchanged.
- Parameters
-
scip SCIP pointer conshdlr constraint handler nconss number of constraints conss indicator constraints sol solution to be enforced (NULL for LP solution) enfosepatype type of enforcing/separating type genlogicor whether logicor constraint should be generated result result
Definition at line 4092 of file cons_indicator.c.
References branchCons(), enforceCuts(), FALSE, NULL, propIndicator(), SCIP_Bool, SCIP_BRANCHED, SCIP_CALL, SCIP_CONSADDED, SCIP_CUTOFF, SCIP_FEASIBLE, SCIP_INFEASIBLE, SCIP_OKAY, SCIP_Real, SCIP_REDUCEDDOM, SCIP_SEPARATED, SCIP_VARSTATUS_MULTAGGR, SCIPallowStrongDualReds(), SCIPcalcChildEstimate(), SCIPchgVarLbNode(), SCIPchgVarUbNode(), SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPcreateChild(), SCIPdebugMsg, SCIPgetSolVal(), SCIPinfoMessage(), SCIPisFeasNegative(), SCIPisFeasZero(), SCIPprintCons(), SCIPresetConsAge(), SCIPvarGetLbLocal(), SCIPvarGetStatus(), SCIPvarGetUbLocal(), SCIPwriteTransProblem(), separateIISRounding(), and TRUE.
Referenced by enforceCuts(), SCIP_DECL_CONSENFOLP(), SCIP_DECL_CONSENFOPS(), and SCIP_DECL_CONSENFORELAX().
◆ separateIISRounding()
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separate IIS-cuts via rounding
- Parameters
-
scip SCIP pointer conshdlr constraint handler sol solution to be separated enfosepatype type of enforcing/separating type nconss number of constraints conss indicator constraints maxsepacuts maximal number of cuts to be generated cutoff whether we detected a cutoff by an infeasible inequality nGen number of domain changes
Definition at line 4282 of file cons_indicator.c.
References checkLPBoundsClean(), extendToCover(), FALSE, fixAltLPVariables(), NULL, scaleFirstRow(), SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconsGetData(), SCIPconshdlrGetData(), SCIPdebug, SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetVarSol(), SCIPhashmapExists(), SCIPisFeasEQ(), SCIPisFeasLT(), SCIPisFeasZero(), SCIPvarGetNegatedVar(), separatePerspective(), setAltLPObj(), TRUE, unfixAltLPVariables(), updateFirstRow(), updateObjUpperbound(), and varGetObjDelta().
Referenced by enforceIndicators(), and separateIndicators().
◆ separatePerspective()
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separate cuts based on perspective formulation
Hijazi, Bonami, and Ouorou (2014) introduced the following cuts: We consider an indicator constraint
\[ y = 1 \rightarrow \alpha^T x \leq \beta \]
and assume finite bounds \(\ell \leq x \leq u\). Then for \(I \subseteq \{1, \dots, n\}\) define
\[ \Sigma(I,x,y) = \sum_{i \notin I} \alpha_i x_i + y \Big(\sum_{i \in I, \alpha_i < 0} \alpha_i u_i + \sum_{i \in I, \alpha_i > 0} \alpha_i \ell_i + \sum_{i \notin I, \alpha_i < 0} \alpha_i \ell_i + \sum_{i \notin I, \alpha_i > 0} \alpha_i u_i - \beta\Big). \]
Then the cuts
\[ \Sigma(I,x,y) \leq \sum_{i \notin I, \alpha_i < 0} \alpha_i \ell_i + \sum_{i \notin I, \alpha_i > 0} \alpha_i u_i \]
are valid for the disjunction
\[ \{y = 0,\; \ell \leq x \leq u\} \cup \{y = 1,\; \ell \leq x \leq u,\; \alpha^T x \leq \beta\}. \]
These cuts can easily be separated for a given point \((x^*, y^*)\) by checking for each \(i \in \{1, \dots, n\}\) whether
\[ y^*(\alpha_i\, u_i\, [\alpha_i < 0] + \alpha_i\, \ell_i\, [\alpha_i > 0]) > \alpha_i x_i^* + y^* )\alpha_i \ell_i [\alpha_i < 0] + \alpha_i u_i [\alpha_i > 0]), \]
where \([C] = 1\) if condition \(C\) is satisfied, otherwise it is 0. If the above inequality holds, \(i\) is included in \(I\), otherwise not.
- Parameters
-
scip SCIP pointer conshdlr constraint handler sol solution to be separated nconss number of constraints conss indicator constraints maxsepacuts maximal number of cuts to be generated nGen number of generated cuts
Definition at line 4494 of file cons_indicator.c.
References FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIP_Real, SCIPaddRow(), SCIPaddVarsToRow(), SCIPallocBufferArray, SCIPconsGetData(), SCIPconshdlrGetData(), SCIPconsIsActive(), SCIPcreateEmptyRowCons(), SCIPdebugMsg, SCIPfreeBufferArray, SCIPgetLhsLinear(), SCIPgetNVars(), SCIPgetNVarsLinear(), SCIPgetRhsLinear(), SCIPgetSolVal(), SCIPgetValsLinear(), SCIPgetVarsLinear(), SCIPinfinity(), SCIPisEfficacious(), SCIPisGT(), SCIPisInfinity(), SCIPisNegative(), SCIPisPositive(), SCIPprintRow(), SCIPreleaseRow(), SCIPresetConsAge(), SCIPsnprintf(), SCIPvarGetLbGlobal(), SCIPvarGetLbLocal(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), separateIndicators(), and TRUE.
Referenced by separateIISRounding(), and separateIndicators().
◆ separateIndicators()
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separation method
We first check whether coupling inequalities can be separated (if required). If not enough of these could be generated, we check whether IIS inequalities can be separated.
- Parameters
-
scip SCIP pointer conshdlr constraint handler nconss number of constraints nusefulconss number of useful constraints conss indicator constraints sol solution to be separated enfosepatype type of enforcing/separating type result result
Definition at line 4695 of file cons_indicator.c.
References FALSE, initConshdlrData(), NULL, SCIP_Bool, SCIP_CALL, SCIP_CONSADDED, SCIP_CUTOFF, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_SEPARATED, SCIPaddRow(), SCIPaddVarToRow(), SCIPcacheRowExtensions(), SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPcreateEmptyRowCons(), SCIPdebugMsg, SCIPflushRowExtensions(), SCIPgetDepth(), SCIPgetSolVal(), SCIPinfinity(), SCIPisEfficacious(), SCIPisFeasNegative(), SCIPprintRow(), SCIPreleaseRow(), SCIPresetConsAge(), SCIPsnprintf(), SCIPvarGetUbGlobal(), SCIPvarGetUbLocal(), SEPAALTTHRESHOLD, separateIISRounding(), separatePerspective(), and TRUE.
Referenced by SCIP_DECL_CONSSEPALP(), SCIP_DECL_CONSSEPASOL(), and separatePerspective().
◆ initConshdlrData()
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initializes the constraint handler data
- Parameters
-
scip SCIP pointer conshdlrdata constraint handler data
Definition at line 4865 of file cons_indicator.c.
References FALSE, MAXROUNDINGROUNDS, NULL, SCIP_DECL_LINCONSUPGD(), SCIPinfinity(), and TRUE.
Referenced by SCIP_DECL_CONSINIT(), SCIPincludeConshdlrIndicator(), and separateIndicators().
◆ SCIP_DECL_LINCONSUPGD()
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tries to upgrade a linear constraint into an indicator constraint
For some linear constraint of the form \(a^T x + \alpha\, y \geq \beta\) with \(y \in \{0,1\}\), we can upgrade it to an indicator constraint if for the residual value \(a^T x \geq \gamma\), we have \(\alpha + \gamma \geq \beta\): in this case, the constraint is always satisfied if \(y = 1\).
Similarly, for a linear constraint in the form \(a^T x + \alpha\, y \leq \beta\) with \(y \in \{0,1\}\), we can upgrade it to an indicator constraint if for the residual value \(a^T x \leq \gamma\), we have \(\alpha + \gamma \leq \beta\).
Definition at line 4916 of file cons_indicator.c.
References FALSE, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_DECL_CONSHDLRCOPY(), SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconsIsChecked(), SCIPconsIsDynamic(), SCIPconsIsEnforced(), SCIPconsIsInitial(), SCIPconsIsLocal(), SCIPconsIsModifiable(), SCIPconsIsPropagated(), SCIPconsIsRemovable(), SCIPconsIsSeparated(), SCIPconsIsStickingAtNode(), SCIPcreateConsIndicator(), SCIPdebugMsg, SCIPfindConshdlr(), SCIPfreeBufferArray, SCIPgetLinearConsIndicator(), SCIPgetNegatedVar(), SCIPinfinity(), SCIPinfoMessage(), SCIPisEQ(), SCIPisGE(), SCIPisInfinity(), SCIPisLE(), SCIPisZero(), SCIPprintCons(), SCIPvarGetLbGlobal(), SCIPvarGetUbGlobal(), SCIPvarIsBinary(), and TRUE.
Referenced by initConshdlrData().
◆ SCIP_DECL_CONSHDLRCOPY()
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copy method for constraint handler plugins (called when SCIP copies plugins)
Definition at line 5145 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_DECL_CONSINIT(), SCIP_OKAY, SCIPconshdlrGetName(), SCIPincludeConshdlrIndicator(), and TRUE.
Referenced by SCIP_DECL_LINCONSUPGD().
◆ SCIP_DECL_CONSINIT()
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initialization method of constraint handler (called after problem was transformed)
Definition at line 5163 of file cons_indicator.c.
References CONSHDLR_NAME, initConshdlrData(), NULL, SCIP_DECL_CONSEXIT(), SCIP_OKAY, SCIPconshdlrGetData(), SCIPconshdlrGetName(), and SCIPfindHeur().
Referenced by SCIP_DECL_CONSHDLRCOPY().
◆ SCIP_DECL_CONSEXIT()
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deinitialization method of constraint handler (called before transformed problem is freed)
Definition at line 5188 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_DECL_CONSFREE(), SCIP_OKAY, SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPfreeBlockMemoryArrayNull, and SCIPhashmapFree().
Referenced by SCIP_DECL_CONSINIT().
◆ SCIP_DECL_CONSFREE()
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destructor of constraint handler to free constraint handler data (called when SCIP is exiting)
Definition at line 5212 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_DECL_CONSINITSOL(), SCIP_OKAY, SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPfreeBlockMemory, and SCIPfreeBlockMemoryArrayNull.
Referenced by SCIP_DECL_CONSEXIT().
◆ SCIP_DECL_CONSINITSOL()
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solving process initialization method of constraint handler (called when branch and bound process is about to begin)
Definition at line 5245 of file cons_indicator.c.
References addAltLPConstraint(), CONSHDLR_NAME, FALSE, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_DECL_CONSEXITSOL(), SCIP_ERROR, SCIP_EVENTTYPE_BESTSOLFOUND, SCIP_EXPRCURV_UNKNOWN, SCIP_OKAY, SCIP_Real, SCIP_REAL_MAX, SCIP_STATUS_INFEASIBLE, SCIP_STATUS_INFORUNBD, SCIP_STATUS_OPTIMAL, SCIP_STATUS_UNBOUNDED, SCIPaddNlRow(), SCIPallocBufferArray, SCIPblkmem(), SCIPcatchEvent(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetNActiveConss(), SCIPconshdlrGetName(), SCIPconshdlrGetSepaFreq(), SCIPconsIsActive(), SCIPconsIsChecked(), SCIPconsIsModifiable(), SCIPconsIsTransformed(), SCIPcreateExprProduct(), SCIPcreateExprVar(), SCIPcreateNlRow(), SCIPdebugMsg, SCIPdisableCons(), SCIPerrorMessage, SCIPfindConshdlr(), SCIPfreeBufferArray, SCIPgetCharParam(), SCIPgetConss(), SCIPgetNConss(), SCIPgetNVars(), SCIPgetStatus(), SCIPgetTransformedCons(), SCIPgetVars(), SCIPhashmapCreate(), SCIPhashmapExists(), SCIPhashmapInsertInt(), SCIPinfoMessage(), SCIPisGE(), SCIPisIntegral(), SCIPisNLPConstructed(), SCIPisZero(), SCIPprintCons(), SCIPreleaseExpr(), SCIPreleaseNlRow(), SCIPvarGetNegatedVar(), SCIPvarGetObj(), SCIPvarGetProbindex(), SCIPvarIsNegated(), SCIPwarningMessage(), TRUE, and varGetObjDelta().
Referenced by SCIP_DECL_CONSFREE().
◆ SCIP_DECL_CONSEXITSOL()
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solving process deinitialization method of constraint handler (called before branch and bound process data is freed)
Definition at line 5561 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_DECL_CONSDELETE(), SCIP_OKAY, SCIPconsGetData(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPgetMessagehdlr(), SCIPhashmapFree(), SCIPhashmapPrintStatistics(), SCIPinfoMessage(), and SCIPlpiFree().
Referenced by SCIP_DECL_CONSINITSOL().
◆ SCIP_DECL_CONSDELETE()
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frees specific constraint data
Definition at line 5633 of file cons_indicator.c.
References CONSHDLR_NAME, deleteAltLPConstraint(), NULL, SCIP_CALL, SCIP_DECL_CONSTRANS(), SCIP_EVENTTYPE_BOUNDCHANGED, SCIP_EVENTTYPE_GBDCHANGED, SCIP_OKAY, SCIP_STAGE_EXITSOLVE, SCIP_STAGE_TRANSFORMING, SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconsIsTransformed(), SCIPdebugMsg, SCIPdropVarEvent(), SCIPfreeBlockMemory, SCIPgetStage(), SCIPreleaseCons(), and SCIPreleaseVar().
Referenced by SCIP_DECL_CONSEXITSOL().
◆ SCIP_DECL_CONSTRANS()
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transforms constraint data into data belonging to the transformed problem
Definition at line 5697 of file cons_indicator.c.
References consdataCreate(), CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_DECL_CONSINITPRE(), SCIP_INVALIDDATA, SCIP_MAXSTRLEN, SCIP_OKAY, SCIPblkmem(), SCIPcaptureCons(), SCIPcaptureVar(), SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconsIsChecked(), SCIPconsIsDynamic(), SCIPconsIsEnforced(), SCIPconsIsInitial(), SCIPconsIsLocal(), SCIPconsIsModifiable(), SCIPconsIsPropagated(), SCIPconsIsRemovable(), SCIPconsIsSeparated(), SCIPconsIsStickingAtNode(), SCIPcreateCons(), SCIPdebugMsg, SCIPerrorMessage, SCIPgetNOrigVars(), SCIPhashmapCreate(), SCIPhashmapExists(), SCIPhashmapInsert(), SCIPsnprintf(), and TRUE.
Referenced by SCIP_DECL_CONSDELETE().
◆ SCIP_DECL_CONSINITPRE()
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presolving initialization method of constraint handler (called when presolving is about to begin)
Definition at line 5783 of file cons_indicator.c.
References CONSHDLR_NAME, FALSE, NULL, SCIP_CALL, SCIP_DECL_CONSPRESOL(), SCIP_OKAY, SCIP_STATUS_UNKNOWN, SCIPcaptureCons(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconsIsTransformed(), SCIPdebugMsg, SCIPgetStatus(), SCIPgetTransformedCons(), and SCIPreleaseCons().
Referenced by SCIP_DECL_CONSTRANS().
◆ SCIP_DECL_CONSPRESOL()
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presolving method of constraint handler
For an indicator constraint with binary variable \(y\) and slack variable \(s\) the coupling inequality \(s \le M (1-y)\) (equivalently: \(s + M y \le M\)) is inserted, where \(M\) is an upper bound on the value of \(s\). If \(M\) is too large the inequality is not inserted. Depending on the parameter addcouplingcons we add a variable upper bound or a row (in consInitlpIndicator()).
- Warning
- We can never delete linear constraints, because we need them to get the right values for the slack variables!
Definition at line 5849 of file cons_indicator.c.
References CONSHDLR_NAME, createVarUbs(), FALSE, NULL, presolRoundIndicator(), SCIP_Bool, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_CUTOFF, SCIP_DECL_CONSINITLP(), SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_Real, SCIP_SUCCESS, SCIP_VARTYPE_CONTINUOUS, SCIP_VARTYPE_IMPLINT, SCIPaddVarImplication(), SCIPallowStrongDualReds(), SCIPchgVarType(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPconsIsModifiable(), SCIPconsIsTransformed(), SCIPdebug, SCIPdebugMsg, SCIPgetNVarsLinear(), SCIPgetValsLinear(), SCIPgetVarsLinear(), SCIPisInfinity(), SCIPisIntegral(), SCIPvarGetLbGlobal(), SCIPvarGetName(), SCIPvarGetType(), SCIPvarGetUbGlobal(), SCIPvarIsIntegral(), and TRUE.
Referenced by SCIP_DECL_CONSINITPRE().
◆ SCIP_DECL_CONSINITLP()
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LP initialization method of constraint handler (called before the initial LP relaxation at a node is solved)
For an indicator constraint with binary variable \(y\) and slack variable \(s\) the coupling inequality \(s \le M (1-y)\) (equivalently: \(s + M y \le M\)) is inserted, where \(M\) is an upper bound on the value of \(s\). If \(M\) is too large the inequality is not inserted.
Definition at line 6028 of file cons_indicator.c.
References CONSHDLR_NAME, FALSE, NULL, SCIP_CALL, SCIP_DECL_CONSSEPALP(), SCIP_OKAY, SCIP_Real, SCIPaddCons(), SCIPaddRow(), SCIPaddVarToRow(), SCIPcacheRowExtensions(), SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPcreateConsVarbound(), SCIPcreateEmptyRowCons(), SCIPdebugMsg, SCIPflushRowExtensions(), SCIPinfinity(), SCIPisNegative(), SCIPprintRow(), SCIPreleaseCons(), SCIPreleaseRow(), SCIPsnprintf(), SCIPvarGetUbGlobal(), and TRUE.
Referenced by SCIP_DECL_CONSPRESOL().
◆ SCIP_DECL_CONSSEPALP()
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separation method of constraint handler for LP solutions
Definition at line 6124 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_DECL_CONSSEPASOL(), SCIP_OKAY, SCIP_TYPE_SEPALP, SCIPconshdlrGetName(), and separateIndicators().
Referenced by SCIP_DECL_CONSINITLP().
◆ SCIP_DECL_CONSSEPASOL()
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separation method of constraint handler for arbitrary primal solutions
Definition at line 6141 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_DECL_CONSENFOLP(), SCIP_OKAY, SCIP_TYPE_SEPASOL, SCIPconshdlrGetName(), and separateIndicators().
Referenced by SCIP_DECL_CONSSEPALP().
◆ SCIP_DECL_CONSENFOLP()
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constraint enforcing method of constraint handler for LP solutions
Definition at line 6158 of file cons_indicator.c.
References CONSHDLR_NAME, enforceIndicators(), NULL, SCIP_CALL, SCIP_DECL_CONSENFORELAX(), SCIP_FEASIBLE, SCIP_OKAY, SCIP_TYPE_ENFOLP, SCIPconshdlrGetData(), and SCIPconshdlrGetName().
Referenced by SCIP_DECL_CONSSEPASOL().
◆ SCIP_DECL_CONSENFORELAX()
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constraint enforcing method of constraint handler for relaxation solutions
Definition at line 6186 of file cons_indicator.c.
References CONSHDLR_NAME, enforceIndicators(), NULL, SCIP_CALL, SCIP_DECL_CONSENFOPS(), SCIP_FEASIBLE, SCIP_OKAY, SCIP_TYPE_ENFORELAX, SCIPconshdlrGetData(), and SCIPconshdlrGetName().
Referenced by SCIP_DECL_CONSENFOLP().
◆ SCIP_DECL_CONSENFOPS()
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constraint enforcing method of constraint handler for pseudo solutions
Definition at line 6214 of file cons_indicator.c.
References CONSHDLR_NAME, enforceIndicators(), NULL, SCIP_CALL, SCIP_DECL_CONSCHECK(), SCIP_DIDNOTRUN, SCIP_FEASIBLE, SCIP_OKAY, SCIP_TYPE_ENFOPS, SCIPconshdlrGetName(), and TRUE.
Referenced by SCIP_DECL_CONSENFORELAX().
◆ SCIP_DECL_CONSCHECK()
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feasibility check method of constraint handler for integral solutions
Definition at line 6242 of file cons_indicator.c.
References checkAltLPInfeasible(), checkLPBoundsClean(), CONSHDLR_NAME, FALSE, fixAltLPVariables(), NULL, REALABS, scaleFirstRow(), SCIP_Bool, SCIP_CALL, SCIP_CALL_PARAM, SCIP_DECL_CONSPROP(), SCIP_FEASIBLE, SCIP_INFEASIBLE, SCIP_LPERROR, SCIP_LPPAR_FROMSCRATCH, SCIP_OKAY, SCIP_Real, SCIP_STAGE_PROBLEM, SCIP_STAGE_SOLVED, SCIPallocBufferArray, SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPcreateSolCopy(), SCIPdebugMsg, SCIPfreeBufferArray, SCIPfreeSol(), SCIPgetSolVal(), SCIPgetStage(), SCIPheurPassSolTrySol(), SCIPinfoMessage(), SCIPisFeasIntegral(), SCIPisFeasZero(), SCIPlpiSetIntpar(), SCIPmakeIndicatorFeasible(), SCIPprintCons(), SCIPrelDiff(), SCIPresetConsAge(), SCIPupdateSolConsViolation(), SCIPvarGetName(), setAltLPObjZero(), TRUE, unfixAltLPVariables(), and updateFirstRowGlobal().
Referenced by SCIP_DECL_CONSENFOPS().
◆ SCIP_DECL_CONSPROP()
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domain propagation method of constraint handler
Definition at line 6441 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, propIndicator(), SCIP_Bool, SCIP_CALL, SCIP_CUTOFF, SCIP_DECL_CONSRESPROP(), SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_OKAY, SCIP_REDUCEDDOM, SCIPallowStrongDualReds(), SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdebugMsg, and SCIPisTransformed().
Referenced by SCIP_DECL_CONSCHECK().
◆ SCIP_DECL_CONSRESPROP()
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propagation conflict resolving method of constraint handler
We check which bound changes were the reason for infeasibility. We use that inferinfo is 0 if the binary variable has bounds that fix it to be nonzero (these bounds are the reason). Likewise inferinfo is 1 if the slack variable has bounds that fix it to be nonzero.
Definition at line 6508 of file cons_indicator.c.
References CONSHDLR_NAME, FALSE, NULL, SCIP_CALL, SCIP_DECL_CONSLOCK(), SCIP_DIDNOTFIND, SCIP_OKAY, SCIP_SUCCESS, SCIPaddConflictLb(), SCIPaddConflictUb(), SCIPallowStrongDualReds(), SCIPallowWeakDualReds(), SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdebugMsg, SCIPgetVarLbAtIndex(), SCIPgetVarUbAtIndex(), SCIPisFeasZero(), and SCIPisPositive().
Referenced by SCIP_DECL_CONSPROP().
◆ SCIP_DECL_CONSLOCK()
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variable rounding lock method of constraint handler
The up-rounding of the binary and slack variable may violate the constraint. If the linear constraint is not active, we lock all variables in the depending constraint - otherwise they will be fixed by dual presolving methods.
Definition at line 6564 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, REALABS, SCIP_Bool, SCIP_CALL, SCIP_DECL_CONSPRINT(), SCIP_OKAY, SCIP_Real, SCIPaddVarLocksType(), SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetName(), SCIPdebugMsg, SCIPgetLhsLinear(), SCIPgetNVarsLinear(), SCIPgetRhsLinear(), SCIPgetValsLinear(), SCIPgetVarsLinear(), SCIPisInfinity(), SCIPisPositive(), and SCIPisZero().
Referenced by SCIP_DECL_CONSRESPROP().
◆ SCIP_DECL_CONSPRINT()
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constraint display method of constraint handler
Definition at line 6640 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_DECL_CONSCOPY(), SCIP_OKAY, SCIP_VARSTATUS_NEGATED, SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetName(), SCIPinfoMessage(), SCIPvarGetName(), SCIPvarGetNegatedVar(), and SCIPvarGetStatus().
Referenced by SCIP_DECL_CONSLOCK().
◆ SCIP_DECL_CONSCOPY()
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constraint copying method of constraint handler
Definition at line 6675 of file cons_indicator.c.
References CONSHDLR_NAME, FALSE, NULL, SCIP_CALL, SCIP_DECL_CONSPARSE(), SCIP_OKAY, SCIP_VERBLEVEL_MINIMAL, SCIPaddCons(), SCIPcaptureCons(), SCIPconsGetData(), SCIPconsGetHdlr(), SCIPconsGetName(), SCIPconshdlrGetName(), SCIPconsIsChecked(), SCIPconsIsDeleted(), SCIPconsIsDynamic(), SCIPconsIsEnforced(), SCIPconsIsInitial(), SCIPconsIsLocal(), SCIPconsIsModifiable(), SCIPconsIsPropagated(), SCIPconsIsRemovable(), SCIPconsIsSeparated(), SCIPconsIsStickingAtNode(), SCIPconsIsTransformed(), SCIPcreateConsIndicatorGenericLinCons(), SCIPcreateConsLinear(), SCIPdebugMsg, SCIPfindConshdlr(), SCIPgetConsCopy(), SCIPgetTransformedCons(), SCIPgetVarCopy(), SCIPinfinity(), SCIPisTransformed(), SCIPreleaseCons(), SCIPverbMessage(), SCIPwarningMessage(), and TRUE.
Referenced by SCIP_DECL_CONSPRINT().
◆ SCIP_DECL_CONSPARSE()
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constraint parsing method of constraint handler
Definition at line 6802 of file cons_indicator.c.
References FALSE, NULL, SCIP_CALL, SCIP_DECL_CONSENABLE(), SCIP_OKAY, SCIP_VERBLEVEL_MINIMAL, SCIPconsGetHdlr(), SCIPconshdlrGetName(), SCIPcreateConsIndicatorLinCons(), SCIPfindCons(), SCIPfindVar(), SCIPgetLhsLinear(), SCIPgetNegatedVar(), SCIPgetRhsLinear(), SCIPisInfinity(), SCIPsnprintf(), SCIPverbMessage(), and TRUE.
Referenced by SCIP_DECL_CONSCOPY().
◆ SCIP_DECL_CONSENABLE()
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constraint enabling notification method of constraint handler
Definition at line 6934 of file cons_indicator.c.
References CONSHDLR_NAME, NULL, SCIP_CALL, SCIP_DECL_CONSDISABLE(), SCIP_OKAY, SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), SCIPdebugMsg, and unfixAltLPVariable().
Referenced by SCIP_DECL_CONSPARSE().
◆ SCIP_DECL_CONSDISABLE()
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constraint disabling notification method of constraint handler
Definition at line 6970 of file cons_indicator.c.
References CONSHDLR_NAME, fixAltLPVariable(), NULL, SCIP_CALL, SCIP_DECL_CONSGETVARS(), SCIP_OKAY, SCIPconsGetData(), SCIPconsGetName(), SCIPconshdlrGetData(), SCIPconshdlrGetName(), and SCIPdebugMsg.
Referenced by SCIP_DECL_CONSENABLE().
◆ SCIP_DECL_CONSGETVARS()
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constraint method of constraint handler which returns the variables (if possible)
Definition at line 7006 of file cons_indicator.c.
References NULL, SCIP_CALL, SCIP_DECL_CONSGETNVARS(), SCIP_INVALIDDATA, SCIP_OKAY, SCIPconsGetData(), SCIPconsIsDeleted(), SCIPgetConsVars(), and TRUE.
Referenced by SCIP_DECL_CONSDISABLE().
◆ SCIP_DECL_CONSGETNVARS()
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constraint method of constraint handler which returns the number of variables (if possible)
Definition at line 7053 of file cons_indicator.c.
References NULL, SCIP_CALL, SCIP_DECL_CONSGETDIVEBDCHGS(), SCIP_OKAY, SCIPconsGetData(), SCIPconsIsDeleted(), SCIPgetConsNVars(), and TRUE.
Referenced by SCIP_DECL_CONSGETVARS().
◆ SCIP_DECL_CONSGETDIVEBDCHGS()
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constraint handler method to suggest dive bound changes during the generic diving algorithm
Definition at line 7097 of file cons_indicator.c.
References CONSHDLR_NAME, FALSE, NULL, SCIP_Bool, SCIP_BRANCHDIR_DOWNWARDS, SCIP_BRANCHDIR_UPWARDS, SCIP_CALL, SCIP_DIVETYPE_INTEGRALITY, SCIP_OKAY, SCIP_Real, SCIP_REAL_MIN, SCIPaddDiveBoundChange(), SCIPconshdlrGetConss(), SCIPconshdlrGetName(), SCIPconshdlrGetNConss(), SCIPgetBinaryVarIndicator(), SCIPgetDivesetScore(), SCIPgetSolVal(), SCIPincludeConshdlrIndicator(), SCIPisFeasIntegral(), SCIPisViolatedIndicator(), SCIPvarGetLbLocal(), SCIPvarGetUbLocal(), and TRUE.
Referenced by SCIP_DECL_CONSGETNVARS().