Scippy

SCIP

Solving Constraint Integer Programs

type_nlhdlr.h File Reference

Detailed Description

type definitions related to nonlinear handlers of nonlinear constraints

Author
Ksenia Bestuzheva
Benjamin Mueller
Felipe Serrano
Stefan Vigerske

This file defines the interface for nonlinear handlers.

Definition in file type_nlhdlr.h.

#include "scip/type_expr.h"
#include "scip/type_cons.h"
#include "scip/type_misc.h"

Go to the source code of this file.

Macros

#define SCIP_NLHDLR_METHOD_NONE   0x0u
 
#define SCIP_NLHDLR_METHOD_SEPABELOW   0x1u
 
#define SCIP_NLHDLR_METHOD_SEPAABOVE   0x2u
 
#define SCIP_NLHDLR_METHOD_SEPABOTH   (SCIP_NLHDLR_METHOD_SEPABELOW | SCIP_NLHDLR_METHOD_SEPAABOVE)
 
#define SCIP_NLHDLR_METHOD_ACTIVITY   0x4u
 
#define SCIP_NLHDLR_METHOD_ALL   (SCIP_NLHDLR_METHOD_SEPABOTH | SCIP_NLHDLR_METHOD_ACTIVITY)
 
#define SCIP_DECL_NLHDLRCOPYHDLR(x)
 
#define SCIP_DECL_NLHDLRFREEHDLRDATA(x)
 
#define SCIP_DECL_NLHDLRFREEEXPRDATA(x)
 
#define SCIP_DECL_NLHDLRINIT(x)
 
#define SCIP_DECL_NLHDLREXIT(x)
 
#define SCIP_DECL_NLHDLRDETECT(x)
 
#define SCIP_DECL_NLHDLREVALAUX(x)
 
#define SCIP_DECL_NLHDLRINTEVAL(x)
 
#define SCIP_DECL_NLHDLRREVERSEPROP(x)
 
#define SCIP_DECL_NLHDLRINITSEPA(x)
 
#define SCIP_DECL_NLHDLREXITSEPA(x)
 
#define SCIP_DECL_NLHDLRENFO(x)
 
#define SCIP_DECL_NLHDLRESTIMATE(x)
 

Typedefs

typedef unsigned int SCIP_NLHDLR_METHOD
 
typedef struct SCIP_Nlhdlr SCIP_NLHDLR
 
typedef struct SCIP_NlhdlrData SCIP_NLHDLRDATA
 
typedef struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
 

Macro Definition Documentation

◆ SCIP_NLHDLR_METHOD_NONE

#define SCIP_NLHDLR_METHOD_NONE   0x0u

no enforcement

Definition at line 50 of file type_nlhdlr.h.

Referenced by detectNlhdlr(), and SCIP_DECL_NLHDLRDETECT().

◆ SCIP_NLHDLR_METHOD_SEPABELOW

#define SCIP_NLHDLR_METHOD_SEPABELOW   0x1u

separation for expr <= auxvar, thus might estimate expr from below

Definition at line 51 of file type_nlhdlr.h.

Referenced by addTightEstimatorCuts(), createNlhdlrExprData(), detectNlhdlr(), enforceExpr(), SCIP_DECL_EXPR_OWNERPRINT(), SCIP_DECL_NLHDLRDETECT(), and SCIP_DECL_NLHDLRENFO().

◆ SCIP_NLHDLR_METHOD_SEPAABOVE

#define SCIP_NLHDLR_METHOD_SEPAABOVE   0x2u

separation for expr >= auxvar, thus might estimate expr from above

Definition at line 52 of file type_nlhdlr.h.

Referenced by addTightEstimatorCuts(), createNlhdlrExprData(), detectNlhdlr(), enforceExpr(), SCIP_DECL_EXPR_OWNERPRINT(), SCIP_DECL_NLHDLRDETECT(), and SCIP_DECL_NLHDLRENFO().

◆ SCIP_NLHDLR_METHOD_SEPABOTH

#define SCIP_NLHDLR_METHOD_SEPABOTH   (SCIP_NLHDLR_METHOD_SEPABELOW | SCIP_NLHDLR_METHOD_SEPAABOVE)

separation for expr == auxvar

Definition at line 53 of file type_nlhdlr.h.

Referenced by analyzeViolation(), detectNlhdlr(), enforceExpr(), initSepa(), SCIP_DECL_NLHDLRDETECT(), and SCIP_DECL_NLHDLREVALAUX().

◆ SCIP_NLHDLR_METHOD_ACTIVITY

#define SCIP_NLHDLR_METHOD_ACTIVITY   0x4u

activity computation (interval evaluation) and propagation (reverse propagation)

Definition at line 54 of file type_nlhdlr.h.

Referenced by detectNlhdlr(), forwardPropExpr(), propExprDomains(), reversePropQueue(), SCIP_DECL_EXPR_OWNERPRINT(), and SCIP_DECL_NLHDLRDETECT().

◆ SCIP_NLHDLR_METHOD_ALL

#define SCIP_NLHDLR_METHOD_ALL   (SCIP_NLHDLR_METHOD_SEPABOTH | SCIP_NLHDLR_METHOD_ACTIVITY)

all enforcement methods

Definition at line 55 of file type_nlhdlr.h.

Referenced by detectNlhdlr(), and SCIP_DECL_NLHDLRDETECT().

◆ SCIP_DECL_NLHDLRCOPYHDLR

#define SCIP_DECL_NLHDLRCOPYHDLR (   x)
Value:
SCIP* targetscip, \
SCIP_CONSHDLR* targetconshdlr, \
SCIP_CONSHDLR* sourceconshdlr, \
SCIP_NLHDLR* sourcenlhdlr)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63

nonlinear handler copy callback

The method includes the nonlinear handler into a nonlinear constraint handler.

This method is usually called when doing a copy of a nonlinear constraint handler.

Parameters
[in]targetsciptarget SCIP main data structure
[in]targetconshdlrtarget nonlinear constraint handler
[out]sourceconshdlrnonlinear constraint handler in source SCIP
[out]sourcenlhdlrnonlinear handler in source SCIP

Definition at line 70 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRFREEHDLRDATA

#define SCIP_DECL_NLHDLRFREEHDLRDATA (   x)
Value:
SCIP* scip, \
SCIP_NLHDLR* nlhdlr, \
SCIP_NLHDLRDATA** nlhdlrdata)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
struct SCIP_NlhdlrData SCIP_NLHDLRDATA
Definition: type_nlhdlr.h:412

callback to free data of handler

Parameters
[in]scipSCIP data structure
[in]nlhdlrnonlinear handler
[in]nlhdlrdatanonlinear handler data to be freed

Definition at line 82 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRFREEEXPRDATA

#define SCIP_DECL_NLHDLRFREEEXPRDATA (   x)
Value:
SCIP* scip, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA** nlhdlrexprdata)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

callback to free expression specific data

Parameters
[in]scipSCIP data structure
[in]nlhdlrnonlinear handler
[in]exprexpression
[in]nlhdlrexprdatanonlinear handler expression data to be freed

Definition at line 94 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRINIT

#define SCIP_DECL_NLHDLRINIT (   x)
Value:
SCIP* scip, \
SCIP_NLHDLR* nlhdlr)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63

callback to be called in initialization (called after problem was transformed)

Parameters
[in]scipSCIP data structure
[in]nlhdlrnonlinear handler

Definition at line 105 of file type_nlhdlr.h.

Referenced by SCIP_DECL_NLHDLRFREEEXPRDATA().

◆ SCIP_DECL_NLHDLREXIT

#define SCIP_DECL_NLHDLREXIT (   x)
Value:
SCIP* scip, \
SCIP_NLHDLR* nlhdlr)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63

callback to be called in deinitialization (called before transformed problem is freed)

Parameters
[in]scipSCIP data structure
[in]nlhdlrnonlinear handler

Definition at line 114 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRDETECT

#define SCIP_DECL_NLHDLRDETECT (   x)
Value:
SCIP* scip, \
SCIP_CONSHDLR* conshdlr, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_CONS* cons, \
SCIP_NLHDLR_METHOD* enforcing, \
SCIP_NLHDLR_METHOD* participating, \
SCIP_NLHDLREXPRDATA** nlhdlrexprdata)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
unsigned int SCIP_NLHDLR_METHOD
Definition: type_nlhdlr.h:57
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

callback to detect structure in expression

The nonlinear handler shall analyze the current expression and decide whether it wants to contribute in enforcing the relation between this expression (expr) and its descendants (e.g., children) via linear under- or overestimation, cut generation, and/or activity computation and propagation. For linear under- or overestimation and cut generation, an auxiliary variable (auxvar) can be assumed to be associated with expr and auxiliary variables may be requested in descendant expressions.

We distinguish the following enforcement methods:

On input, parameter enforcing indicates for any of these methods, whether

  • it is not necessary to have such a method, e.g., because no auxvar will exist for expr, or no one uses or sets activities of this expression, or because analysis of the expression has shown that a relation like exprauxvar is not necessary to be satisfied,
  • or there already exists a nonlinear handler that will provide this method in an "enforcement" sense, that is, it believes that no one else could provide this method in a stronger sense. (This is mainly used by nlhdlr_default to check whether it should still reach out to the exprhdlr or whether it would be dominated by some nonlinear handler.)

The DETECT callback shall augment the enforcing bitmask by setting the enforcement methods it wants to provide in an "enforcement" sense.

Additionally, the participating bitmask shall be set if the nonlinear handler wants to be called on this expression at all. Here, it shall set all methods that it wants to provide, which are those set in enforcing, but additionally those where it wants to participate but leave enforcement to another nonlinear handler. This can be useful for nonlinear handlers that do not implement a complete enforcement, e.g., a handler that only contributes cutting planes in some situations only.

A nonlinear handler will be called only for those callbacks that it mentioned in participating, which is

If SCIP_NLHDLR_METHOD_SEPABELOW or SCIP_NLHDLR_METHOD_SEPAABOVE has been set, then at least one of the callbacks ENFO and ESTIMATE needs to be implemented. Also EVALAUX will be called in this case. If SCIP_NLHDLR_METHOD_ACTIVITY has been set, then at least one of INTEVAL and REVERSEPROP needs to be implemented. If the nonlinear handler chooses not to participate, then it must not set nlhdlrexprdata and can leave participating at its initial value (SCIP_NLHDLR_METHOD_NONE).

Additionally, a nonlinear handler that decides to participate in any of the enforcement methods must call SCIPregisterExprUsageNonlinear() for every subexpression that it will use and indicate whether

  • it will use an auxiliary variable in ENFO or ESTIMATE,
  • it will use activity for some subexpressions when computing estimators or cuts, and
  • it will use activity for some subexpressions when in INTEVAL or REVERSEPROP.
Note
Auxiliary variables do not exist in subexpressions during DETECT and are not created by a call to SCIPregisterExprUsageNonlinear(). They will be available when the INITSEPA callback is called.
Parameters
[in]scipSCIP data structure
[in]conshdlrnonlinear constraint handler
[in]nlhdlrnonlinear handler
[in]exprexpression to analyze
[in]consthe constraint that expression defines, or NULL when the expr does not define any constraint, that is, when it is not the root of an expression of a constraint
[in,out]enforcingenforcement methods that are provided by some nonlinear handler (to be updated by detect callback)
[out]participatingenforcement methods that this nonlinear handler should be called for (to be set by detect callback), initialized to SCIP_NLHDLR_METHOD_NONE
[out]nlhdlrexprdatanlhdlr's expr data to be stored in expr, can only be set to non-NULL if success is set to TRUE

Definition at line 177 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLREVALAUX

#define SCIP_DECL_NLHDLREVALAUX (   x)
Value:
SCIP* scip, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA* nlhdlrexprdata, \
SCIP_Real* auxvalue, \
SCIP_SOL* sol)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
#define SCIP_Real
Definition: def.h:186
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

auxiliary evaluation callback of nonlinear handler

Evaluates the expression w.r.t. the auxiliary variables that were introduced by the nonlinear handler (if any). The method is used to determine the violation of the relation that the nonlinear handler attempts to enforce. During enforcement, this violation value is used to decide whether estimation/separation callbacks should be called.

It can be assumed that the expression itself has been evaluated in the given sol.

Parameters
[in]scipSCIP data structure
[in]nlhdlrnonlinear handler
[in]exprexpression to evaluate
[in]nlhdlrexprdataexpression specific data of the nonlinear handler
[out]auxvaluebuffer to store value of expression w.r.t. auxiliary variables
[in]solpoint to evaluate

Definition at line 202 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRINTEVAL

#define SCIP_DECL_NLHDLRINTEVAL (   x)
Value:
SCIP* scip, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA* nlhdlrexprdata, \
SCIP_INTERVAL* interval, \
SCIP_DECL_EXPR_INTEVALVAR((*intevalvar)), \
void* intevalvardata)
#define SCIP_DECL_EXPR_INTEVALVAR(x)
Definition: type_expr.h:160
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

nonlinear handler interval evaluation (activity computation) callback

The method computes an interval that contains the image (range) of the expression.

Parameters
[in]scipSCIP main data structure
[in]nlhdlrnonlinear handler
[in]exprexpression
[in]nlhdlrexprdataexpression specific data of the nonlinear handler
[in,out]intervalbuffer where to store interval (on input: current interval for expr, on output: computed interval for expr)
[in]intevalvarcallback to be called when interval evaluating a variable
[in]intevalvardatadata to be passed to intevalvar callback

Definition at line 222 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRREVERSEPROP

#define SCIP_DECL_NLHDLRREVERSEPROP (   x)
Value:
SCIP* scip, \
SCIP_CONSHDLR* conshdlr, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA* nlhdlrexprdata, \
SCIP_INTERVAL bounds, \
SCIP_Bool* infeasible, \
int* nreductions)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
#define SCIP_Bool
Definition: def.h:93
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

nonlinear handler callback for reverse propagation

The method propagates the given bounds over the arguments of an expression. The arguments of an expression are other expressions and the tighter intervals should be passed to the corresponding argument (expression) via SCIPtightenExprIntervalNonlinear().

Parameters
[in]scipSCIP main data structure
[in]conshdlrnonlinear constraint handler
[in]nlhdlrnonlinear handler
[in]exprexpression
[in]nlhdlrexprdataexpression specific data of the nonlinear handler
[in]boundsthe bounds on the expression that should be propagated
[out]infeasiblebuffer to store whether an expression's bounds were propagated to an empty interval
[out]nreductionsbuffer to store the number of interval reductions of all children

Definition at line 246 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRINITSEPA

#define SCIP_DECL_NLHDLRINITSEPA (   x)
Value:
SCIP* scip, \
SCIP_CONSHDLR* conshdlr, \
SCIP_CONS* cons, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA* nlhdlrexprdata, \
SCIP_Bool overestimate, \
SCIP_Bool underestimate, \
SCIP_Bool* infeasible)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
#define SCIP_Bool
Definition: def.h:93
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

separation initialization method of a nonlinear handler (called during CONSINITLP)

The method shall initialize the separation data of the nonlinear handler, if any, and add initial cuts to the LP relaxation.

Parameters
[in]scipSCIP main data structure
[in]conshdlrnonlinear constraint handler
[in]consnonlinear constraint
[in]nlhdlrnonlinear handler
[in]nlhdlrexprdataexprdata of nonlinear handler
[in]exprexpression
[in]overestimatewhether the expression needs to be overestimated
[in]underestimatewhether the expression needs to be underestimated
[out]infeasiblebuffer to store whether infeasibility was detected while building the LP

Definition at line 270 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLREXITSEPA

#define SCIP_DECL_NLHDLREXITSEPA (   x)
Value:
SCIP* scip, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA* nlhdlrexprdata)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

separation deinitialization method of a nonlinear handler (called during CONSEXITSOL)

The method shall deinitialize the separation data of the nonlinear handler, if any.

Parameters
[in]scipSCIP main data structure
[in]nlhdlrnonlinear handler
[in]nlhdlrexprdataexprdata of nonlinear handler
[in]exprexpression

Definition at line 290 of file type_nlhdlr.h.

Referenced by SCIP_DECL_NLHDLRINITSEPA().

◆ SCIP_DECL_NLHDLRENFO

#define SCIP_DECL_NLHDLRENFO (   x)
Value:
SCIP* scip, \
SCIP_CONSHDLR* conshdlr, \
SCIP_CONS* cons, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA* nlhdlrexprdata, \
SCIP_SOL* sol, \
SCIP_Real auxvalue, \
SCIP_Bool overestimate, \
SCIP_Bool allowweakcuts, \
SCIP_Bool separated, \
SCIP_Bool addbranchscores, \
SCIP_RESULT* result)
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:61
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
#define SCIP_Bool
Definition: def.h:93
#define SCIP_Real
Definition: def.h:186
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

nonlinear handler separation and enforcement callback

The method tries to separate the given solution from the set defined by either

  expr - auxvar <= 0 (if !overestimate)

or

  expr - auxvar >= 0 (if  overestimate),

where auxvar = SCIPgetExprAuxVarNonlinear(expr).

It can do so by

  • separation, i.e., finding an affine hyperplane (a cut) that separates the given point,
  • bound tightening, i.e., changing bounds on a variable so that the given point is outside the updated domain,
  • adding branching scores to potentially split the current problem into 2 subproblems

If parameter inenforcement is FALSE, then only the first option (separation) is allowed.

If the nonlinear handler always separates by computing a linear under- or overestimator of expr, then it could be advantageous to implement the ESTIMATE callback instead.

Note, that the nonlinear handler may also choose to separate for a relaxation of the mentioned sets, e.g., expr ≤ upperbound(auxvar) or expr ≥ lowerbound(auxvar). This is especially useful in situations where expr is the root expression of a constraint and it is sufficient to satisfy lhsexprrhs. cons_nonlinear ensures that lhs ≤ lowerbound(auxvar) and upperbound(auxvar) ≤ rhs.

cons_nonlinear may call this callback first with allowweakcuts = FALSE and repeat later with allowweakcuts = TRUE, if it didn't succeed to enforce a solution without using weak cuts. If in enforcement and the nonlinear handler cannot enforce by separation or bound tightening, it should register branching scores for those expressions where branching may help to compute tighter cuts in children.

The nonlinear handler must set result to SCIP_SEPARATED if it added a cut, to SCIP_REDUCEDDOM if it added a bound change, and to SCIP_BRANCHED if it added branching scores. Otherwise, it may set result to SCIP_DIDNOTRUN or SCIP_DIDNOTFIND.

Parameter cons gives the constraint that is currently enforced. Note that expr does not need to be the root of this constraint, i.e., SCIPgetExprNonlinear(cons)==expr may not hold. If an expression appears in several constraints, it is not well defined which constraint is given in cons. The main purpose of cons is to provide a constraint source for LP rows that are added in this callback.

Parameters
[in]scipSCIP main data structure
[in]conshdlrnonlinear constraint handler
[in]consnonlinear constraint that is currently enforced
[in]nlhdlrnonlinear handler
[in]exprexpression
[in]nlhdlrexprdataexpression specific data of the nonlinear handler
[in]solsolution to be separated (NULL for the LP solution)
[in]auxvaluecurrent value of expression w.r.t. auxiliary variables as obtained from EVALAUX
[in]overestimatewhether the expression needs to be over- or underestimated
[in]allowweakcutswhether we should only look for "strong" cuts, or anything that separates is fine
[in]separatedwhether another nonlinear handler already added a cut for this expression
[in]inenforcementwhether we are in enforcement, or only in separation
[out]resultpointer to store the result

Definition at line 353 of file type_nlhdlr.h.

◆ SCIP_DECL_NLHDLRESTIMATE

#define SCIP_DECL_NLHDLRESTIMATE (   x)
Value:
SCIP* scip, \
SCIP_CONSHDLR* conshdlr, \
SCIP_NLHDLR* nlhdlr, \
SCIP_EXPR* expr, \
SCIP_NLHDLREXPRDATA* nlhdlrexprdata, \
SCIP_SOL* sol, \
SCIP_Real auxvalue, \
SCIP_Bool overestimate, \
SCIP_Real targetvalue, \
SCIP_Bool addbranchscores, \
SCIP_PTRARRAY* rowpreps, \
SCIP_Bool* success, \
SCIP_Bool* addedbranchscores)
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_VAR ** x
Definition: circlepacking.c:63
#define SCIP_Bool
Definition: def.h:93
#define SCIP_Real
Definition: def.h:186
struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA
Definition: type_nlhdlr.h:413

nonlinear handler under/overestimation callback

The method tries to compute linear under- or overestimators of expr that are as tight as possible at a given point. If the value of the estimator in the solution is smaller (larger) than targetvalue when underestimating (overestimating), then no estimator needs to be computed. Note, that targetvalue can be infinite if any estimator will be accepted. If successful, it shall store the estimators in the given rowpreps data structure and set the rowprep->local flag accordingly (SCIProwprepSetLocal()). The sidetype of a rowprep must be set to SCIP_SIDETYPE_LEFT if overestimating and SCIP_SIDETYPE_RIGHT if underestimating.

If the callback is required to indicate for which expression a reduction in the local bounds (usually by branching) would improve the estimator, it shall do so via calls to SCIPaddExprsViolScoreNonlinear().

Parameters
[in]scipSCIP main data structure
[in]conshdlrconstraint handler
[in]nlhdlrnonlinear handler
[in]exprexpression
[in]nlhdlrexprdataexpression data of nonlinear handler
[in]solsolution at which to estimate (NULL for the LP solution)
[in]auxvaluecurrent value of expression w.r.t. auxiliary variables as obtained from EVALAUX
[in]overestimatewhether the expression needs to be over- or underestimated
[in]targetvaluea value the estimator shall exceed, can be +/-infinity
[in]addbranchscoresindicates whether to register branching scores
[out]rowprepsan array where to store the estimators
[out]successbuffer to indicate whether an estimator could be computed
[out]addedbranchscoresbuffer to store whether the branching score callback was successful

Definition at line 396 of file type_nlhdlr.h.

Typedef Documentation

◆ SCIP_NLHDLR_METHOD

typedef unsigned int SCIP_NLHDLR_METHOD

nlhdlr methods bitflags

Definition at line 57 of file type_nlhdlr.h.

◆ SCIP_NLHDLR

typedef struct SCIP_Nlhdlr SCIP_NLHDLR

nonlinear handler

Definition at line 411 of file type_nlhdlr.h.

◆ SCIP_NLHDLRDATA

typedef struct SCIP_NlhdlrData SCIP_NLHDLRDATA

nonlinear handler data

Definition at line 412 of file type_nlhdlr.h.

◆ SCIP_NLHDLREXPRDATA

typedef struct SCIP_NlhdlrExprData SCIP_NLHDLREXPRDATA

nonlinear handler data for a specific expression

Definition at line 413 of file type_nlhdlr.h.