heur_randrounding.c
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18 * @brief randomized LP rounding heuristic which also generates conflicts via an auxiliary probing tree
25 * This implementation uses domain propagation techniques to tighten the variable domains after every
29 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
65 #define DEFAULT_USESIMPLEROUNDING FALSE /**< should the heuristic apply the variable lock strategy of simple rounding,
68 #define DEFAULT_PROPAGATEONLYROOT TRUE /**< should the probing part of the heuristic be applied exclusively at the root node */
78 SCIP_Bool usesimplerounding; /**< should the heuristic apply the variable lock strategy of simple rounding,
80 SCIP_Bool propagateonlyroot; /**< should the probing part of the heuristic be applied exclusively at the root node? */
87 /** perform randomized rounding of the given solution. Domain propagation is optionally applied after every rounding
184 /* choose rounding direction, if possible, or use the only direction guaranteed to be feasible */
204 /* if propagation is enabled, fix the candidate variable to its rounded value and propagate the solution */
317 /* only call heuristic, if LP solution is fractional; except we are called during pricing, in this case we
421 /** solving process initialization method of primal heuristic (called when branch and bound process is about to begin) */
424 {
441 /** solving process deinitialization method of primal heuristic (called before branch and bound process data is freed) */
444 {
520 SCIP_CALL( SCIPaddBoolParam(scip, "heuristics/" HEUR_NAME "/usesimplerounding", "should the heuristic apply the variable lock strategy of simple rounding, if possible?",
Definition: type_result.h:33
Definition: type_result.h:47
static SCIP_DECL_HEUREXIT(heurExitRandrounding)
Definition: heur_randrounding.c:405
SCIP_RETCODE SCIPsetSolVal(SCIP *scip, SCIP_SOL *sol, SCIP_VAR *var, SCIP_Real val)
Definition: scip_sol.c:1213
public methods for SCIP parameter handling
void SCIPfreeRandom(SCIP *scip, SCIP_RANDNUMGEN **randnumgen)
Definition: scip_randnumgen.c:70
SCIP_Bool SCIPisGE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
Definition: scip_numerics.c:490
Definition: struct_scip.h:59
SCIP_RETCODE SCIPsetHeurExitsol(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEUREXITSOL((*heurexitsol)))
Definition: scip_heur.c:233
public methods for memory management
static SCIP_RETCODE performRandRounding(SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_SOL *sol, SCIP_VAR **cands, int ncands, SCIP_Bool propagate, SCIP_RESULT *result)
Definition: heur_randrounding.c:92
SCIP_RETCODE SCIPincludeHeurRandrounding(SCIP *scip)
Definition: heur_randrounding.c:494
SCIP_Real SCIPgetSolVal(SCIP *scip, SCIP_SOL *sol, SCIP_VAR *var)
Definition: scip_sol.c:1353
Definition: struct_var.h:198
SCIP_Real SCIPrandomGetReal(SCIP_RANDNUMGEN *randnumgen, SCIP_Real minrandval, SCIP_Real maxrandval)
Definition: misc.c:9967
static SCIP_DECL_HEUREXEC(heurExecRandrounding)
Definition: heur_randrounding.c:454
Definition: struct_misc.h:259
SCIP_Bool SCIPisFeasLE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
Definition: scip_numerics.c:799
public methods for problem variables
SCIP_RETCODE SCIPaddBoolParam(SCIP *scip, const char *name, const char *desc, SCIP_Bool *valueptr, SCIP_Bool isadvanced, SCIP_Bool defaultvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:48
#define SCIP_HEURTIMING_DURINGPRICINGLOOP
Definition: type_timing.h:85
#define SCIPduplicateBufferArray(scip, ptr, source, num)
Definition: scip_mem.h:119
public methods for SCIP variables
SCIP_RETCODE SCIPsetHeurInit(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURINIT((*heurinit)))
Definition: scip_heur.c:185
SCIP_RETCODE SCIPtrySol(SCIP *scip, SCIP_SOL *sol, SCIP_Bool printreason, SCIP_Bool completely, SCIP_Bool checkbounds, SCIP_Bool checkintegrality, SCIP_Bool checklprows, SCIP_Bool *stored)
Definition: scip_sol.c:3125
SCIP_Bool SCIPisFeasIntegral(SCIP *scip, SCIP_Real val)
Definition: scip_numerics.c:874
public methods for numerical tolerances
SCIP_RETCODE SCIPcreateRandom(SCIP *scip, SCIP_RANDNUMGEN **randnumgen, unsigned int initialseed, SCIP_Bool useglobalseed)
Definition: scip_randnumgen.c:47
SCIP_RETCODE SCIPcreateSol(SCIP *scip, SCIP_SOL **sol, SCIP_HEUR *heur)
Definition: scip_sol.c:320
public methods for querying solving statistics
Definition: struct_sol.h:64
SCIP_RETCODE SCIPincludeHeurBasic(SCIP *scip, SCIP_HEUR **heur, const char *name, const char *desc, char dispchar, int priority, int freq, int freqofs, int maxdepth, SCIP_HEURTIMING timingmask, SCIP_Bool usessubscip, SCIP_DECL_HEUREXEC((*heurexec)), SCIP_HEURDATA *heurdata)
Definition: scip_heur.c:108
public methods for the branch-and-bound tree
static SCIP_DECL_HEURCOPY(heurCopyRandrounding)
Definition: heur_randrounding.c:351
Definition: type_result.h:35
SCIP_Bool SCIPisFeasEQ(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
Definition: scip_numerics.c:773
static SCIP_DECL_HEUREXITSOL(heurExitsolRandrounding)
Definition: heur_randrounding.c:444
Definition: type_var.h:42
void SCIPheurSetData(SCIP_HEUR *heur, SCIP_HEURDATA *heurdata)
Definition: heur.c:1350
void SCIPheurSetTimingmask(SCIP_HEUR *heur, SCIP_HEURTIMING timingmask)
Definition: heur.c:1469
Definition: type_retcode.h:33
Definition: struct_heur.h:88
static SCIP_DECL_HEURFREE(heurFreeRandrounding)
Definition: heur_randrounding.c:365
Definition: type_lp.h:34
public methods for primal heuristic plugins and divesets
public data structures and miscellaneous methods
SCIP_RETCODE SCIPsetHeurExit(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEUREXIT((*heurexit)))
Definition: scip_heur.c:201
SCIP_RETCODE SCIPpropagateProbing(SCIP *scip, int maxproprounds, SCIP_Bool *cutoff, SCIP_Longint *ndomredsfound)
Definition: scip_probing.c:571
static SCIP_RETCODE performLPRandRounding(SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_HEURTIMING heurtiming, SCIP_Bool propagate, SCIP_RESULT *result)
Definition: heur_randrounding.c:295
SCIP_Bool SCIPisFeasGE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
Definition: scip_numerics.c:825
public methods for the LP relaxation, rows and columns
public methods for branching rule plugins and branching
general public methods
public methods for solutions
public methods for random numbers
public methods for the probing mode
SCIP_RETCODE SCIPsetHeurCopy(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURCOPY((*heurcopy)))
Definition: scip_heur.c:153
public methods for message output
SCIP_RETCODE SCIPaddIntParam(SCIP *scip, const char *name, const char *desc, int *valueptr, SCIP_Bool isadvanced, int defaultvalue, int minvalue, int maxvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:74
SCIP_RETCODE SCIPchgVarLbProbing(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound)
Definition: scip_probing.c:292
SCIP_RETCODE SCIPprintSol(SCIP *scip, SCIP_SOL *sol, FILE *file, SCIP_Bool printzeros)
Definition: scip_sol.c:1767
static SCIP_DECL_HEURINIT(heurInitRandrounding)
Definition: heur_randrounding.c:384
SCIP_RETCODE SCIPchgVarUbProbing(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound)
Definition: scip_probing.c:336
SCIP_Bool SCIPisLT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
Definition: scip_numerics.c:451
public methods for message handling
SCIP_Bool SCIPisGT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
Definition: scip_numerics.c:477
SCIP_RETCODE SCIPgetLPBranchCands(SCIP *scip, SCIP_VAR ***lpcands, SCIP_Real **lpcandssol, SCIP_Real **lpcandsfrac, int *nlpcands, int *npriolpcands, int *nfracimplvars)
Definition: scip_branch.c:386
SCIP_RETCODE SCIPsetHeurInitsol(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURINITSOL((*heurinitsol)))
Definition: scip_heur.c:217
SCIP_RETCODE SCIPsetHeurFree(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURFREE((*heurfree)))
Definition: scip_heur.c:169
randomized LP rounding heuristic which also generates conflicts via an auxiliary probing tree ...
public methods for primal heuristics
Definition: objbenders.h:33
void SCIPrandomPermuteArray(SCIP_RANDNUMGEN *randnumgen, void **array, int begin, int end)
Definition: misc.c:10016
static SCIP_DECL_HEURINITSOL(heurInitsolRandrounding)
Definition: heur_randrounding.c:424
memory allocation routines