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heur.h File Reference

Detailed Description

internal methods for primal heuristics

Author
Tobias Achterberg

Definition in file heur.h.

#include "scip/def.h"
#include "blockmemshell/memory.h"
#include "scip/type_retcode.h"
#include "scip/type_result.h"
#include "scip/type_set.h"
#include "scip/type_primal.h"
#include "scip/type_heur.h"
#include "scip/pub_heur.h"
#include "scip/stat.h"

Go to the source code of this file.

Functions

SCIP_RETCODE SCIPdivesetCreate (SCIP_DIVESET **divesetptr, SCIP_HEUR *heur, const char *name, SCIP_SET *set, SCIP_MESSAGEHDLR *messagehdlr, BMS_BLKMEM *blkmem, SCIP_Real minreldepth, SCIP_Real maxreldepth, SCIP_Real maxlpiterquot, SCIP_Real maxdiveubquot, SCIP_Real maxdiveavgquot, SCIP_Real maxdiveubquotnosol, SCIP_Real maxdiveavgquotnosol, SCIP_Real lpresolvedomchgquot, int lpsolvefreq, int maxlpiterofs, unsigned int initialseed, SCIP_Bool backtrack, SCIP_Bool onlylpbranchcands, SCIP_Bool ispublic, SCIP_DIVETYPE divetypemask, SCIP_DECL_DIVESETGETSCORE((*divesetgetscore)),)
SCIP_RETCODE SCIPdivesetReset (SCIP_DIVESET *diveset, SCIP_SET *set)
void SCIPdivesetUpdateStats (SCIP_DIVESET *diveset, SCIP_STAT *stat, int depth, int nprobingnodes, int nbacktracks, SCIP_Longint nsolsfound, SCIP_Longint nbestsolsfound, SCIP_Longint nconflictsfound, SCIP_Bool leavesol, SCIP_DIVECONTEXT divecontext)
SCIP_RETCODE SCIPdivesetGetScore (SCIP_DIVESET *diveset, SCIP_SET *set, SCIP_DIVETYPE divetype, SCIP_VAR *divecand, SCIP_Real divecandsol, SCIP_Real divecandfrac, SCIP_Real *candscore, SCIP_Bool *roundup)
SCIP_RETCODE SCIPdivesetIsAvailable (SCIP_DIVESET *diveset, SCIP_SET *set, SCIP_Bool *available)
void SCIPdivesetUpdateLPStats (SCIP_DIVESET *diveset, SCIP_STAT *stat, SCIP_Longint niterstoadd, SCIP_DIVECONTEXT divecontext)
SCIP_RETCODE SCIPheurCopyInclude (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE SCIPheurCreate (SCIP_HEUR **heur, SCIP_SET *set, SCIP_MESSAGEHDLR *messagehdlr, BMS_BLKMEM *blkmem, const char *name, const char *desc, char dispchar, int priority, int freq, int freqofs, int maxdepth, SCIP_HEURTIMING timingmask, SCIP_Bool usessubscip, SCIP_DECL_HEURCOPY((*heurcopy)), SCIP_DECL_HEURFREE((*heurfree)), SCIP_DECL_HEURINIT((*heurinit)), SCIP_DECL_HEUREXIT((*heurexit)), SCIP_DECL_HEURINITSOL((*heurinitsol)), SCIP_DECL_HEUREXITSOL((*heurexitsol)), SCIP_DECL_HEUREXEC((*heurexec)), SCIP_HEURDATA *heurdata)
SCIP_RETCODE SCIPheurFree (SCIP_HEUR **heur, SCIP_SET *set, BMS_BLKMEM *blkmem)
SCIP_RETCODE SCIPheurInit (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE SCIPheurExit (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE SCIPheurInitsol (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_RETCODE SCIPheurExitsol (SCIP_HEUR *heur, SCIP_SET *set)
SCIP_Bool SCIPheurShouldBeExecuted (SCIP_HEUR *heur, int depth, int lpstateforkdepth, SCIP_HEURTIMING heurtiming, SCIP_Bool *delayed)
SCIP_RETCODE SCIPheurExec (SCIP_HEUR *heur, SCIP_SET *set, SCIP_PRIMAL *primal, int depth, int lpstateforkdepth, SCIP_HEURTIMING heurtiming, SCIP_Bool nodeinfeasible, int *ndelayedheurs, SCIP_RESULT *result)
void SCIPheurSetPriority (SCIP_HEUR *heur, SCIP_SET *set, int priority)
void SCIPheurSetCopy (SCIP_HEUR *heur,)
void SCIPheurSetFree (SCIP_HEUR *heur,)
void SCIPheurSetInit (SCIP_HEUR *heur,)
void SCIPheurSetExit (SCIP_HEUR *heur,)
void SCIPheurSetInitsol (SCIP_HEUR *heur,)
void SCIPheurSetExitsol (SCIP_HEUR *heur,)
void SCIPheurEnableOrDisableClocks (SCIP_HEUR *heur, SCIP_Bool enable)

Function Documentation

◆ SCIPdivesetCreate()

SCIP_RETCODE SCIPdivesetCreate ( SCIP_DIVESET ** divesetptr,
SCIP_HEUR * heur,
const char * name,
SCIP_SET * set,
SCIP_MESSAGEHDLR * messagehdlr,
BMS_BLKMEM * blkmem,
SCIP_Real minreldepth,
SCIP_Real maxreldepth,
SCIP_Real maxlpiterquot,
SCIP_Real maxdiveubquot,
SCIP_Real maxdiveavgquot,
SCIP_Real maxdiveubquotnosol,
SCIP_Real maxdiveavgquotnosol,
SCIP_Real lpresolvedomchgquot,
int lpsolvefreq,
int maxlpiterofs,
unsigned int initialseed,
SCIP_Bool backtrack,
SCIP_Bool onlylpbranchcands,
SCIP_Bool ispublic,
SCIP_DIVETYPE divetypemask,
SCIP_DECL_DIVESETGETSCORE((*divesetgetscore))  )

create a set of diving heuristic settings

Parameters
divesetptrpointer to the freshly created diveset
heurthe heuristic to which this dive setting belongs
namename for the diveset, or NULL if the name of the heuristic should be used
setglobal SCIP settings
messagehdlrmessage handler
blkmemblock memory for parameter settings
minreldepthminimal relative depth to start diving
maxreldepthmaximal relative depth to start diving
maxlpiterquotmaximal fraction of diving LP iterations compared to node LP iterations
maxdiveubquotmaximal quotient (curlowerbound - lowerbound)/(cutoffbound - lowerbound) where diving is performed (0.0: no limit)
maxdiveavgquotmaximal quotient (curlowerbound - lowerbound)/(avglowerbound - lowerbound) where diving is performed (0.0: no limit)
maxdiveubquotnosolmaximal UBQUOT when no solution was found yet (0.0: no limit)
maxdiveavgquotnosolmaximal AVGQUOT when no solution was found yet (0.0: no limit)
lpresolvedomchgquotpercentage of immediate domain changes during probing to trigger LP resolve
lpsolvefreqLP solve frequency for (0: only if enough domain reductions are found by propagation)
maxlpiterofsadditional number of allowed LP iterations
initialseedinitial seed for random number generation
backtrackuse one level of backtracking if infeasibility is encountered?
onlylpbranchcandsshould only LP branching candidates be considered instead of the slower but more general constraint handler diving variable selection?
ispublicis this dive set publicly available (ie., can be used by other primal heuristics?)
divetypemaskbit mask that represents the supported dive types by this dive set

Definition at line 266 of file heur.c.

References assert(), BMSallocBlockMemory, BMSduplicateMemoryArray, c, diveset, FALSE, heurAddDiveset(), NULL, paramname, SCIP_ALLOC, SCIP_Bool, SCIP_CALL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_Real, SCIP_REAL_MAX, SCIPdivesetReset(), SCIPheurGetName(), SCIPrandomCreate(), SCIPsetAddBoolParam(), SCIPsetAddIntParam(), SCIPsetAddRealParam(), SCIPsnprintf(), and TRUE.

Referenced by SCIPcreateDiveset().

◆ SCIPdivesetReset()

SCIP_RETCODE SCIPdivesetReset ( SCIP_DIVESET * diveset,
SCIP_SET * set )

resets diving settings counters

Parameters
divesetdiveset to be reset
setglobal SCIP settings

Definition at line 130 of file heur.c.

References assert(), diveset, NULL, resetDivesetStats(), SCIP_OKAY, SCIPrandomSetSeed(), and SCIPsetInitializeRandomSeed().

Referenced by SCIPdivesetCreate(), and SCIPheurInit().

◆ SCIPdivesetUpdateStats()

void SCIPdivesetUpdateStats ( SCIP_DIVESET * diveset,
SCIP_STAT * stat,
int depth,
int nprobingnodes,
int nbacktracks,
SCIP_Longint nsolsfound,
SCIP_Longint nbestsolsfound,
SCIP_Longint nconflictsfound,
SCIP_Bool leavesol,
SCIP_DIVECONTEXT divecontext )

update diveset statistics and global diveset statistics

Parameters
divesetdiveset to be reset
statglobal SCIP statistics
depththe depth reached this time
nprobingnodesthe number of probing nodes explored this time
nbacktracksthe number of backtracks during probing this time
nsolsfoundnumber of new solutions found this time
nbestsolsfoundnumber of new best solutions found this time
nconflictsfoundnumber of new conflicts found this time
leavesolhas the diving heuristic reached a feasible leaf
divecontextcontext for diving statistics

Definition at line 203 of file heur.c.

References assert(), c, depth, diveset, divesetGetStats(), SCIP_Stat::ndivesetcalls, nsolsfound, NULL, SCIP_Bool, SCIP_DIVECONTEXT_ADAPTIVE, SCIP_DIVECONTEXT_SCHEDULER, SCIP_DIVECONTEXT_SINGLE, SCIP_DIVECONTEXT_TOTAL, SCIP_Longint, SCIP_Stat::totaldivesetdepth, and updateDivesetstats().

Referenced by SCIPupdateDivesetStats().

◆ SCIPdivesetGetScore()

SCIP_RETCODE SCIPdivesetGetScore ( SCIP_DIVESET * diveset,
SCIP_SET * set,
SCIP_DIVETYPE divetype,
SCIP_VAR * divecand,
SCIP_Real divecandsol,
SCIP_Real divecandfrac,
SCIP_Real * candscore,
SCIP_Bool * roundup )

get the candidate score and preferred rounding direction for a candidate variable

Parameters
divesetgeneral diving settings
setSCIP settings
divetypethe type of diving that should be applied
divecandthe candidate for which the branching direction is requested
divecandsolLP solution value of the candidate
divecandfracfractionality of the candidate
candscorepointer to store the candidate score
rounduppointer to store whether preferred direction for diving is upwards

Definition at line 834 of file heur.c.

References assert(), diveset, NULL, roundup, SCIP_Bool, SCIP_CALL, SCIP_OKAY, and SCIP_Real.

Referenced by SCIPgetDivesetScore().

◆ SCIPdivesetIsAvailable()

SCIP_RETCODE SCIPdivesetIsAvailable ( SCIP_DIVESET * diveset,
SCIP_SET * set,
SCIP_Bool * available )

check specific preconditions for diving, e.g., if an incumbent solution is available

Parameters
divesetdiving heuristic settings
setSCIP settings
availablepointer to store if the diving can run at the current solving stage

Definition at line 858 of file heur.c.

References assert(), diveset, FALSE, NULL, SCIP_Bool, SCIP_CALL, SCIP_OKAY, and TRUE.

Referenced by SCIPisDivesetAvailable().

◆ SCIPdivesetUpdateLPStats()

void SCIPdivesetUpdateLPStats ( SCIP_DIVESET * diveset,
SCIP_STAT * stat,
SCIP_Longint niterstoadd,
SCIP_DIVECONTEXT divecontext )

update diveset LP statistics, should be called after every LP solved by this diving heuristic

Parameters
divesetdiving settings
statglobal SCIP statistics
niterstoaddadditional number of LP iterations to be added
divecontextcontext for diving statistics

Definition at line 787 of file heur.c.

References assert(), diveset, divesetGetStats(), SCIP_Stat::ndivesetlpiterations, SCIP_Stat::ndivesetlps, NULL, SCIP_DIVECONTEXT_ADAPTIVE, SCIP_DIVECONTEXT_SCHEDULER, SCIP_DIVECONTEXT_SINGLE, SCIP_DIVECONTEXT_TOTAL, SCIP_Longint, and updateDivesetstatsLP().

Referenced by SCIPupdateDivesetLPStats().

◆ SCIPheurCopyInclude()

SCIP_RETCODE SCIPheurCopyInclude ( SCIP_HEUR * heur,
SCIP_SET * set )

copies the given primal heuristic to a new scip

Parameters
heurprimal heuristic
setSCIP_SET of SCIP to copy to

Definition at line 882 of file heur.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPheurGetName(), and SCIPsetDebugMsg.

Referenced by SCIPsetCopyPlugins().

◆ SCIPheurCreate()

SCIP_RETCODE SCIPheurCreate ( SCIP_HEUR ** heur,
SCIP_SET * set,
SCIP_MESSAGEHDLR * messagehdlr,
BMS_BLKMEM * blkmem,
const char * name,
const char * desc,
char dispchar,
int priority,
int freq,
int freqofs,
int maxdepth,
SCIP_HEURTIMING timingmask,
SCIP_Bool usessubscip,
SCIP_DECL_HEURCOPY((*heurcopy)) ,
SCIP_DECL_HEURFREE((*heurfree)) ,
SCIP_DECL_HEURINIT((*heurinit)) ,
SCIP_DECL_HEUREXIT((*heurexit)) ,
SCIP_DECL_HEURINITSOL((*heurinitsol)) ,
SCIP_DECL_HEUREXITSOL((*heurexitsol)) ,
SCIP_DECL_HEUREXEC((*heurexec)) ,
SCIP_HEURDATA * heurdata )

creates a primal heuristic

Parameters
heurpointer to primal heuristic data structure
setglobal SCIP settings
messagehdlrmessage handler
blkmemblock memory for parameter settings
namename of primal heuristic
descdescription of primal heuristic
dispchardisplay character of primal heuristic
prioritypriority of the primal heuristic
freqfrequency for calling primal heuristic
freqofsfrequency offset for calling primal heuristic
maxdepthmaximal depth level to call heuristic at (-1: no limit)
timingmaskpositions in the node solving loop where heuristic should be executed
usessubscipdoes the heuristic use a secondary SCIP instance?
heurdataprimal heuristic data

Definition at line 989 of file heur.c.

References assert(), doHeurCreate(), heurdata, maxdepth, NULL, SCIP_Bool, SCIP_CALL_FINALLY, SCIP_DECL_HEURCOPY, SCIP_DECL_HEUREXEC, SCIP_DECL_HEUREXIT, SCIP_DECL_HEUREXITSOL, SCIP_DECL_HEURFREE, SCIP_DECL_HEURINIT, SCIP_DECL_HEURINITSOL, SCIP_OKAY, and SCIPheurFree().

Referenced by SCIPincludeHeur(), and SCIPincludeHeurBasic().

◆ SCIPheurFree()

SCIP_RETCODE SCIPheurFree ( SCIP_HEUR ** heur,
SCIP_SET * set,
BMS_BLKMEM * blkmem )

calls destructor and frees memory of primal heuristic

Parameters
heurpointer to primal heuristic data structure
setglobal SCIP settings
blkmemblock memory

Definition at line 1028 of file heur.c.

References assert(), BMSfreeMemory, BMSfreeMemoryArrayNull, divesetFree(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPclockFree().

Referenced by SCIPheurCreate().

◆ SCIPheurInit()

◆ SCIPheurExit()

SCIP_RETCODE SCIPheurExit ( SCIP_HEUR * heur,
SCIP_SET * set )

calls exit method of primal heuristic

Parameters
heurprimal heuristic
setglobal SCIP settings

Definition at line 1117 of file heur.c.

References assert(), FALSE, SCIP_Heur::initialized, SCIP_Heur::name, NULL, SCIP_CALL, SCIP_INVALIDCALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), SCIPerrorMessage, and SCIP_Heur::setuptime.

◆ SCIPheurInitsol()

SCIP_RETCODE SCIPheurInitsol ( SCIP_HEUR * heur,
SCIP_SET * set )

informs primal heuristic that the branch and bound process is being started

Parameters
heurprimal heuristic
setglobal SCIP settings

Definition at line 1147 of file heur.c.

References assert(), SCIP_Heur::delaypos, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), and SCIP_Heur::setuptime.

◆ SCIPheurExitsol()

SCIP_RETCODE SCIPheurExitsol ( SCIP_HEUR * heur,
SCIP_SET * set )

informs primal heuristic that the branch and bound process data is being freed

Parameters
heurprimal heuristic
setglobal SCIP settings

Definition at line 1177 of file heur.c.

References assert(), NULL, SCIP_CALL, SCIP_OKAY, SCIPclockStart(), SCIPclockStop(), and SCIP_Heur::setuptime.

◆ SCIPheurShouldBeExecuted()

SCIP_Bool SCIPheurShouldBeExecuted ( SCIP_HEUR * heur,
int depth,
int lpstateforkdepth,
SCIP_HEURTIMING heurtiming,
SCIP_Bool * delayed )

should the heuristic be executed at the given depth, frequency, timing, ...

Parameters
heurprimal heuristic
depthdepth of current node
lpstateforkdepthdepth of the last node with solved LP
heurtimingcurrent point in the node solving process
delayedpointer to store whether the heuristic should be delayed

Definition at line 1201 of file heur.c.

References SCIP_Heur::delaypos, depth, FALSE, SCIP_Heur::freq, SCIP_Heur::freqofs, SCIP_Heur::maxdepth, SCIP_Bool, SCIP_HEURTIMING_AFTERLPNODE, SCIP_HEURTIMING_AFTERLPPLUNGE, SCIP_HEURTIMING_AFTERPSEUDONODE, SCIP_HEURTIMING_AFTERPSEUDOPLUNGE, SCIP_HEURTIMING_BEFOREPRESOL, SCIP_HEURTIMING_DURINGPRESOLLOOP, SCIP_Heur::timingmask, and TRUE.

Referenced by SCIPheurExec(), and SCIPprimalHeuristics().

◆ SCIPheurExec()

SCIP_RETCODE SCIPheurExec ( SCIP_HEUR * heur,
SCIP_SET * set,
SCIP_PRIMAL * primal,
int depth,
int lpstateforkdepth,
SCIP_HEURTIMING heurtiming,
SCIP_Bool nodeinfeasible,
int * ndelayedheurs,
SCIP_RESULT * result )

calls execution method of primal heuristic

Parameters
heurprimal heuristic
setglobal SCIP settings
primalprimal data
depthdepth of current node
lpstateforkdepthdepth of the last node with solved LP
heurtimingcurrent point in the node solving process
nodeinfeasiblewas the current node already detected to be infeasible?
ndelayedheurspointer to count the number of delayed heuristics
resultpointer to store the result of the callback method

Definition at line 1263 of file heur.c.

References assert(), SCIP_Heur::delaypos, depth, FALSE, SCIP_Heur::freq, SCIP_Heur::freqofs, SCIP_Heur::heurclock, SCIP_Heur::maxdepth, SCIP_Heur::name, SCIP_Heur::nbestsolsfound, SCIP_Primal::nbestsolsfound, SCIP_Heur::ncalls, SCIP_Heur::nsolsfound, SCIP_Primal::nsolsfound, NULL, result, SCIP_Bool, SCIP_CALL, SCIP_DELAYED, SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_FOUNDSOL, SCIP_HEURTIMING_BEFOREPRESOL, SCIP_HEURTIMING_DURINGPRESOLLOOP, SCIP_INVALIDRESULT, SCIP_Longint, SCIP_OKAY, SCIP_UNBOUNDED, SCIPclockStart(), SCIPclockStop(), SCIPerrorMessage, SCIPheurShouldBeExecuted(), and SCIPsetDebugMsg.

Referenced by SCIPprimalHeuristics().

◆ SCIPheurSetPriority()

void SCIPheurSetPriority ( SCIP_HEUR * heur,
SCIP_SET * set,
int priority )

sets priority of primal heuristic

Parameters
heurprimal heuristic
setglobal SCIP settings
prioritynew priority of the primal heuristic

Definition at line 1524 of file heur.c.

References assert(), FALSE, NULL, and SCIP_Heur::priority.

Referenced by SCIPsetHeurPriority().

◆ SCIPheurSetCopy()

void SCIPheurSetCopy ( SCIP_HEUR * heur)

sets copy callback of primal heuristic

Parameters
heurprimal heuristic copy callback of primal heuristic or NULL if you don't want to copy your plugin into sub-SCIPs

Definition at line 1387 of file heur.c.

References assert(), NULL, and SCIP_DECL_HEURCOPY.

Referenced by SCIPsetHeurCopy().

◆ SCIPheurSetFree()

void SCIPheurSetFree ( SCIP_HEUR * heur)

sets destructor callback of primal heuristic

Parameters
heurprimal heuristic destructor of primal heuristic

Definition at line 1398 of file heur.c.

References assert(), NULL, and SCIP_DECL_HEURFREE.

Referenced by SCIPsetHeurFree().

◆ SCIPheurSetInit()

void SCIPheurSetInit ( SCIP_HEUR * heur)

sets initialization callback of primal heuristic

Parameters
heurprimal heuristic initialize primal heuristic

Definition at line 1409 of file heur.c.

References assert(), NULL, and SCIP_DECL_HEURINIT.

Referenced by SCIPsetHeurInit().

◆ SCIPheurSetExit()

void SCIPheurSetExit ( SCIP_HEUR * heur)

sets deinitialization callback of primal heuristic

Parameters
heurprimal heuristic deinitialize primal heuristic

Definition at line 1420 of file heur.c.

References assert(), NULL, and SCIP_DECL_HEUREXIT.

Referenced by SCIPsetHeurExit().

◆ SCIPheurSetInitsol()

void SCIPheurSetInitsol ( SCIP_HEUR * heur)

sets solving process initialization callback of primal heuristic

Parameters
heurprimal heuristic solving process initialization callback of primal heuristic

Definition at line 1431 of file heur.c.

References assert(), NULL, and SCIP_DECL_HEURINITSOL.

Referenced by SCIPsetHeurInitsol().

◆ SCIPheurSetExitsol()

void SCIPheurSetExitsol ( SCIP_HEUR * heur)

sets solving process deinitialization callback of primal heuristic

Parameters
heurprimal heuristic solving process deinitialization callback of primal heuristic

Definition at line 1442 of file heur.c.

References assert(), NULL, and SCIP_DECL_HEUREXITSOL.

Referenced by SCIPsetHeurExitsol().

◆ SCIPheurEnableOrDisableClocks()

void SCIPheurEnableOrDisableClocks ( SCIP_HEUR * heur,
SCIP_Bool enable )

enables or disables all clocks of heur, depending on the value of the flag

Parameters
heurthe heuristic for which all clocks should be enabled or disabled
enableshould the clocks of the heuristic be enabled?

Definition at line 1619 of file heur.c.

References assert(), SCIP_Heur::heurclock, NULL, SCIP_Bool, SCIPclockEnableOrDisable(), and SCIP_Heur::setuptime.