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    SCIP

    Solving Constraint Integer Programs

    Macros | Functions
    expr_log.c File Reference
    Implementation files (.c files) » SCIP Default Plugins » Default expression handlers

    Detailed Description

    logarithm expression handler

    Author
    Stefan Vigerske
    Benjamin Mueller
    Ksenia Bestuzheva

    Definition in file expr_log.c.

    #include <string.h>
    #include "scip/expr_value.h"
    #include "scip/expr_log.h"

    Go to the source code of this file.

    Macros

    #define EXPRHDLR_NAME   "log"
     
    #define EXPRHDLR_DESC   "natural logarithm expression"
     
    #define EXPRHDLR_PRECEDENCE   80000
     
    #define EXPRHDLR_HASHKEY   SCIPcalcFibHash(16273.0)
     

    Functions

    static void addLogSecant (SCIP *scip, SCIP_Real lb, SCIP_Real ub, SCIP_Real *lincoef, SCIP_Real *linconstant, SCIP_Bool *success)
     
    static void addLogLinearization (SCIP *scip, SCIP_Real refpoint, SCIP_Bool isint, SCIP_Real *lincoef, SCIP_Real *linconstant, SCIP_Bool *success)
     
    static SCIP_DECL_EXPRSIMPLIFY (simplifyLog)
     
    static SCIP_DECL_EXPRCOPYHDLR (copyhdlrLog)
     
    static SCIP_DECL_EXPRFREEHDLR (freehdlrLog)
     
    static SCIP_DECL_EXPRCOPYDATA (copydataLog)
     
    static SCIP_DECL_EXPRFREEDATA (freedataLog)
     
    static SCIP_DECL_EXPRPARSE (parseLog)
     
    static SCIP_DECL_EXPREVAL (evalLog)
     
    static SCIP_DECL_EXPRBWDIFF (bwdiffLog)
     
    static SCIP_DECL_EXPRINTEVAL (intevalLog)
     
    static SCIP_DECL_EXPRESTIMATE (estimateLog)
     
    static SCIP_DECL_EXPRINITESTIMATES (initestimatesLog)
     
    static SCIP_DECL_EXPRREVERSEPROP (reversepropLog)
     
    static SCIP_DECL_EXPRHASH (hashLog)
     
    static SCIP_DECL_EXPRCURVATURE (curvatureLog)
     
    static SCIP_DECL_EXPRMONOTONICITY (monotonicityLog)
     
    SCIP_RETCODE SCIPincludeExprhdlrLog (SCIP *scip)
     
    SCIP_RETCODE SCIPcreateExprLog (SCIP *scip, SCIP_EXPR **expr, SCIP_EXPR *child, SCIP_DECL_EXPR_OWNERCREATE((*ownercreate)), void *ownercreatedata)
     
    SCIP_Bool SCIPisExprLog (SCIP *scip, SCIP_EXPR *expr)
     

    Macro Definition Documentation

    ◆ EXPRHDLR_NAME

    #define EXPRHDLR_NAME   "log"

    Definition at line 41 of file expr_log.c.

    ◆ EXPRHDLR_DESC

    #define EXPRHDLR_DESC   "natural logarithm expression"

    Definition at line 42 of file expr_log.c.

    ◆ EXPRHDLR_PRECEDENCE

    #define EXPRHDLR_PRECEDENCE   80000

    Definition at line 43 of file expr_log.c.

    ◆ EXPRHDLR_HASHKEY

    #define EXPRHDLR_HASHKEY   SCIPcalcFibHash(16273.0)

    Definition at line 44 of file expr_log.c.

    Function Documentation

    ◆ addLogSecant()

    static void addLogSecant ( SCIP *  scip,
    SCIP_Real  lb,
    SCIP_Real  ub,
    SCIP_Real *  lincoef,
    SCIP_Real *  linconstant,
    SCIP_Bool *  success 
    )
    		static

    computes coefficients of secant of a logarithmic term

    Parameters
    scipSCIP data structure
    lblower bound on variable
    ubupper bound on variable
    lincoefbuffer to add coefficient of secant
    linconstantbuffer to add constant of secant
    successbuffer to set to FALSE if secant has failed due to large numbers or unboundedness

    Definition at line 63 of file expr_log.c.

    References FALSE, NULL, REALABS, SCIP_Real, SCIPisEQ(), SCIPisInfinity(), and SCIPisLE().

    Referenced by SCIP_DECL_EXPRESTIMATE(), and SCIP_DECL_EXPRINITESTIMATES().

    ◆ addLogLinearization()

    static void addLogLinearization ( SCIP *  scip,
    SCIP_Real  refpoint,
    SCIP_Bool  isint,
    SCIP_Real *  lincoef,
    SCIP_Real *  linconstant,
    SCIP_Bool *  success 
    )
    		static

    computes coefficients of linearization of a logarithmic term in a reference point

    Parameters
    scipSCIP data structure
    refpointpoint for which to compute value of linearization
    isintwhether corresponding variable is a discrete variable, and thus linearization could be moved
    lincoefbuffer to add coefficient of secant
    linconstantbuffer to add constant of secant
    successbuffer to set to FALSE if secant has failed due to large numbers or unboundedness

    Definition at line 114 of file expr_log.c.

    References FALSE, NULL, REALABS, SCIP_Real, SCIPfloor(), SCIPisInfinity(), SCIPisIntegral(), and SCIPisLE().

    Referenced by SCIP_DECL_EXPRESTIMATE(), and SCIP_DECL_EXPRINITESTIMATES().

    ◆ SCIP_DECL_EXPRSIMPLIFY()

    static SCIP_DECL_EXPRSIMPLIFY ( simplifyLog  )
    		static

    simplifies a log expression

    Evaluates the logarithm function when its child is a value expression.

    TODO: split products ? TODO: log(exp(*)) = *

    Definition at line 178 of file expr_log.c.

    References NULL, SCIP_CALL, SCIP_OKAY, SCIPcaptureExpr(), SCIPcreateExprValue(), SCIPexprGetChildren(), SCIPexprGetNChildren(), SCIPgetValueExprValue(), SCIPisExprValue(), and SCIPisPositive().

    ◆ SCIP_DECL_EXPRCOPYHDLR()

    static SCIP_DECL_EXPRCOPYHDLR ( copyhdlrLog  )
    		static

    expression handler copy callback

    Definition at line 212 of file expr_log.c.

    References SCIP_CALL, SCIP_OKAY, and SCIPincludeExprhdlrLog().

    ◆ SCIP_DECL_EXPRFREEHDLR()

    static SCIP_DECL_EXPRFREEHDLR ( freehdlrLog  )
    		static

    expression handler free callback

    Definition at line 221 of file expr_log.c.

    References NULL, SCIP_OKAY, and SCIPfreeBlockMemory.

    ◆ SCIP_DECL_EXPRCOPYDATA()

    static SCIP_DECL_EXPRCOPYDATA ( copydataLog  )
    		static

    expression data copy callback

    Definition at line 233 of file expr_log.c.

    References NULL, SCIP_OKAY, and SCIPexprGetData().

    ◆ SCIP_DECL_EXPRFREEDATA()

    static SCIP_DECL_EXPRFREEDATA ( freedataLog  )
    		static

    expression data free callback

    Definition at line 246 of file expr_log.c.

    References NULL, SCIP_OKAY, and SCIPexprSetData().

    ◆ SCIP_DECL_EXPRPARSE()

    static SCIP_DECL_EXPRPARSE ( parseLog  )
    		static

    expression parse callback

    Definition at line 257 of file expr_log.c.

    References NULL, SCIP_CALL, SCIP_OKAY, SCIPcreateExprLog(), SCIPparseExpr(), SCIPreleaseExpr(), and TRUE.

    ◆ SCIP_DECL_EXPREVAL()

    static SCIP_DECL_EXPREVAL ( evalLog  )
    		static

    expression point evaluation callback

    ! [SnippetExprEvalLog]

    ! [SnippetExprEvalLog]

    Definition at line 281 of file expr_log.c.

    References NULL, SCIP_INVALID, SCIP_OKAY, SCIPdebugMsg, SCIPexprGetChildren(), SCIPexprGetData(), SCIPexprGetEvalValue(), and SCIPexprGetNChildren().

    ◆ SCIP_DECL_EXPRBWDIFF()

    static SCIP_DECL_EXPRBWDIFF ( bwdiffLog  )
    		static

    expression derivative evaluation callback

    Definition at line 305 of file expr_log.c.

    References NULL, SCIP_INVALID, SCIP_OKAY, SCIPexprGetChildren(), SCIPexprGetEvalValue(), SCIPexprGetHdlr(), and SCIPexprhdlrGetName().

    ◆ SCIP_DECL_EXPRINTEVAL()

    static SCIP_DECL_EXPRINTEVAL ( intevalLog  )
    		static

    expression interval evaluation callback

    Definition at line 325 of file expr_log.c.

    References EXPRHDLR_NAME, SCIP_Interval::inf, NULL, SCIP_CALL, SCIP_INTERVAL_INFINITY, SCIP_OKAY, SCIP_VERBLEVEL_NONE, SCIPexprGetActivity(), SCIPexprGetChildren(), SCIPexprGetData(), SCIPexprGetHdlr(), SCIPexprGetNChildren(), SCIPexprhdlrGetData(), SCIPgetVerbLevel(), SCIPinfoMessage(), SCIPintervalIsEmpty(), SCIPintervalLog(), SCIPintervalSetEmpty(), SCIPprintExpr(), and TRUE.

    ◆ SCIP_DECL_EXPRESTIMATE()

    static SCIP_DECL_EXPRESTIMATE ( estimateLog  )
    		static

    expression estimation callback

    Definition at line 368 of file expr_log.c.

    References addLogLinearization(), addLogSecant(), EXPRHDLR_NAME, FALSE, NULL, SCIP_OKAY, SCIP_Real, SCIPexprGetChildren(), SCIPexprGetHdlr(), SCIPexprGetNChildren(), SCIPexprhdlrGetName(), SCIPexprIsIntegral(), SCIPisPositive(), SCIPisZero(), and TRUE.

    ◆ SCIP_DECL_EXPRINITESTIMATES()

    static SCIP_DECL_EXPRINITESTIMATES ( initestimatesLog  )
    		static

    initial estimates callback that provides initial linear estimators for a logarithm expression

    Definition at line 424 of file expr_log.c.

    References addLogLinearization(), addLogSecant(), EXPRHDLR_NAME, FALSE, MAX, MIN, NULL, SCIP_Bool, SCIP_INVALID, SCIP_OKAY, SCIP_Real, SCIPdebugMsg, SCIPexprGetChildren(), SCIPexprGetHdlr(), SCIPexprGetNChildren(), SCIPexprhdlrGetName(), SCIPexprIsIntegral(), SCIPintervalGetInf(), SCIPintervalGetSup(), SCIPisEQ(), SCIPisGE(), SCIPisInfinity(), SCIPisLE(), and TRUE.

    ◆ SCIP_DECL_EXPRREVERSEPROP()

    static SCIP_DECL_EXPRREVERSEPROP ( reversepropLog  )
    		static

    expression reverse propagation callback

    Definition at line 502 of file expr_log.c.

    References EXPRHDLR_NAME, NULL, SCIP_CALL, SCIP_INTERVAL_INFINITY, SCIP_OKAY, SCIP_VERBLEVEL_NONE, SCIPdebugMsg, SCIPepsilon(), SCIPexprGetHdlr(), SCIPexprGetNChildren(), SCIPexprhdlrGetData(), SCIPgetVerbLevel(), SCIPinfoMessage(), SCIPintervalExp(), SCIPprintExpr(), and TRUE.

    ◆ SCIP_DECL_EXPRHASH()

    static SCIP_DECL_EXPRHASH ( hashLog  )
    		static

    expression hash callback

    Definition at line 545 of file expr_log.c.

    References EXPRHDLR_HASHKEY, NULL, SCIP_OKAY, and SCIPexprGetNChildren().

    ◆ SCIP_DECL_EXPRCURVATURE()

    static SCIP_DECL_EXPRCURVATURE ( curvatureLog  )
    		static

    expression curvature detection callback

    Definition at line 561 of file expr_log.c.

    References FALSE, NULL, SCIP_EXPRCURV_CONCAVE, SCIP_OKAY, SCIPexprGetNChildren(), and TRUE.

    ◆ SCIP_DECL_EXPRMONOTONICITY()

    static SCIP_DECL_EXPRMONOTONICITY ( monotonicityLog  )
    		static

    expression monotonicity detection callback

    Definition at line 582 of file expr_log.c.

    References NULL, SCIP_MONOTONE_INC, and SCIP_OKAY.