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Detailed Description

LP diving heuristic that chooses fixings w.r.t. the pseudo cost values.

Author
Tobias Achterberg

Definition in file heur_pscostdiving.c.

#include "scip/heuristics.h"
#include "scip/heur_pscostdiving.h"
#include "scip/pub_heur.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_var.h"
#include "scip/scip_heur.h"
#include "scip/scip_mem.h"
#include "scip/scip_numerics.h"
#include "scip/scip_prob.h"
#include "scip/scip_sol.h"
#include "scip/scip_var.h"
#include <string.h>

Go to the source code of this file.

Macros

#define HEUR_NAME   "pscostdiving"
 
#define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the pseudo cost values"
 
#define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING
 
#define HEUR_PRIORITY   -1002000
 
#define HEUR_FREQ   10
 
#define HEUR_FREQOFS   2
 
#define HEUR_MAXDEPTH   -1
 
#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE
 
#define HEUR_USESSUBSCIP   FALSE
 
#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY
 
#define DIVESET_ISPUBLIC   TRUE
 
#define DEFAULT_MINRELDEPTH   0.0
 
#define DEFAULT_MAXRELDEPTH   1.0
 
#define DEFAULT_MAXLPITERQUOT   0.05
 
#define DEFAULT_MAXLPITEROFS   1000
 
#define DEFAULT_MAXDIVEUBQUOT   0.8
 
#define DEFAULT_MAXDIVEAVGQUOT   0.0
 
#define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1
 
#define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0
 
#define DEFAULT_BACKTRACK   TRUE
 
#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15
 
#define DEFAULT_LPSOLVEFREQ   0
 
#define DEFAULT_ONLYLPBRANCHCANDS   TRUE
 
#define DEFAULT_RANDSEED   103
 
#define divesetAvailablePscostdiving   NULL
 

Functions

static SCIP_DECL_HEURCOPY (heurCopyPscostdiving)
 
static assert (heur !=NULL)
 
 assert (strcmp(SCIPheurGetName(heur), HEUR_NAME)==0)
 
 assert (scip !=NULL)
 
 assert (heurdata !=NULL)
 
 SCIPfreeBlockMemory (scip, &heurdata)
 
 SCIPheurSetData (heur, NULL)
 
 SCIPcreateSol (scip, &heurdata->sol, heur))
 
 SCIPfreeSol (scip, &heurdata->sol))
 
 assert (SCIPheurGetNDivesets(heur) > 0)
 
 assert (SCIPheurGetDivesets(heur) !=NULL)
 
 assert (diveset !=NULL)
 
 if (SCIPgetNBinVars(scip)+SCIPgetNIntVars(scip)==0)
 
SCIP_RETCODE SCIPincludeHeurPscostdiving (SCIP *scip)
 

Variables

 heurdata = SCIPheurGetData(heur)
 
return SCIP_OKAY
 
static SCIP_DIVESETdiveset
 
result = SCIP_DIDNOTRUN
 

Macro Definition Documentation

◆ HEUR_NAME

#define HEUR_NAME   "pscostdiving"

Definition at line 47 of file heur_pscostdiving.c.

◆ HEUR_DESC

#define HEUR_DESC   "LP diving heuristic that chooses fixings w.r.t. the pseudo cost values"

Definition at line 48 of file heur_pscostdiving.c.

◆ HEUR_DISPCHAR

#define HEUR_DISPCHAR   SCIP_HEURDISPCHAR_DIVING

Definition at line 49 of file heur_pscostdiving.c.

◆ HEUR_PRIORITY

#define HEUR_PRIORITY   -1002000

Definition at line 50 of file heur_pscostdiving.c.

◆ HEUR_FREQ

#define HEUR_FREQ   10

Definition at line 51 of file heur_pscostdiving.c.

◆ HEUR_FREQOFS

#define HEUR_FREQOFS   2

Definition at line 52 of file heur_pscostdiving.c.

◆ HEUR_MAXDEPTH

#define HEUR_MAXDEPTH   -1

Definition at line 53 of file heur_pscostdiving.c.

◆ HEUR_TIMING

#define HEUR_TIMING   SCIP_HEURTIMING_AFTERLPPLUNGE

Definition at line 54 of file heur_pscostdiving.c.

◆ HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP   FALSE

does the heuristic use a secondary SCIP instance?

Definition at line 55 of file heur_pscostdiving.c.

◆ DIVESET_DIVETYPES

#define DIVESET_DIVETYPES   SCIP_DIVETYPE_INTEGRALITY

bit mask that represents all supported dive types

Definition at line 56 of file heur_pscostdiving.c.

◆ DIVESET_ISPUBLIC

#define DIVESET_ISPUBLIC   TRUE

is this dive set publicly available (ie., can be used by other primal heuristics?)

Definition at line 57 of file heur_pscostdiving.c.

◆ DEFAULT_MINRELDEPTH

#define DEFAULT_MINRELDEPTH   0.0

minimal relative depth to start diving

Definition at line 64 of file heur_pscostdiving.c.

◆ DEFAULT_MAXRELDEPTH

#define DEFAULT_MAXRELDEPTH   1.0

maximal relative depth to start diving

Definition at line 65 of file heur_pscostdiving.c.

◆ DEFAULT_MAXLPITERQUOT

#define DEFAULT_MAXLPITERQUOT   0.05

maximal fraction of diving LP iterations compared to node LP iterations

Definition at line 66 of file heur_pscostdiving.c.

◆ DEFAULT_MAXLPITEROFS

#define DEFAULT_MAXLPITEROFS   1000

additional number of allowed LP iterations

Definition at line 67 of file heur_pscostdiving.c.

◆ DEFAULT_MAXDIVEUBQUOT

#define DEFAULT_MAXDIVEUBQUOT   0.8

maximal quotient (curlowerbound - lowerbound)/(cutoffbound - lowerbound) where diving is performed (0.0: no limit)

Definition at line 68 of file heur_pscostdiving.c.

◆ DEFAULT_MAXDIVEAVGQUOT

#define DEFAULT_MAXDIVEAVGQUOT   0.0

maximal quotient (curlowerbound - lowerbound)/(avglowerbound - lowerbound) where diving is performed (0.0: no limit)

Definition at line 70 of file heur_pscostdiving.c.

◆ DEFAULT_MAXDIVEUBQUOTNOSOL

#define DEFAULT_MAXDIVEUBQUOTNOSOL   0.1

maximal UBQUOT when no solution was found yet (0.0: no limit)

Definition at line 72 of file heur_pscostdiving.c.

◆ DEFAULT_MAXDIVEAVGQUOTNOSOL

#define DEFAULT_MAXDIVEAVGQUOTNOSOL   0.0

maximal AVGQUOT when no solution was found yet (0.0: no limit)

Definition at line 73 of file heur_pscostdiving.c.

◆ DEFAULT_BACKTRACK

#define DEFAULT_BACKTRACK   TRUE

use one level of backtracking if infeasibility is encountered?

Definition at line 74 of file heur_pscostdiving.c.

◆ DEFAULT_LPRESOLVEDOMCHGQUOT

#define DEFAULT_LPRESOLVEDOMCHGQUOT   0.15

percentage of immediate domain changes during probing to trigger LP resolve

Definition at line 75 of file heur_pscostdiving.c.

◆ DEFAULT_LPSOLVEFREQ

#define DEFAULT_LPSOLVEFREQ   0

LP solve frequency for diving heuristics

Definition at line 76 of file heur_pscostdiving.c.

◆ DEFAULT_ONLYLPBRANCHCANDS

#define DEFAULT_ONLYLPBRANCHCANDS   TRUE

should only LP branching candidates be considered instead of the slower but more general constraint handler diving variable selection?

Definition at line 77 of file heur_pscostdiving.c.

◆ DEFAULT_RANDSEED

#define DEFAULT_RANDSEED   103

initial random seed

Definition at line 79 of file heur_pscostdiving.c.

◆ divesetAvailablePscostdiving

#define divesetAvailablePscostdiving   NULL

Definition at line 260 of file heur_pscostdiving.c.

Referenced by SCIPincludeHeurPscostdiving().

Function Documentation

◆ SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyPscostdiving )
static

copy method for primal heuristic plugins (called when SCIP copies plugins)

Definition at line 98 of file heur_pscostdiving.c.

References assert(), HEUR_NAME, NULL, SCIP_CALL, SCIP_OKAY, SCIPheurGetName(), and SCIPincludeHeurPscostdiving().

◆ assert() [1/7]

static assert ( heur ! = NULL)

destructor of primal heuristic to free user data (called when SCIP is exiting)

initialization method of primal heuristic (called after problem was transformed)

deinitialization method of primal heuristic (called before transformed problem is freed)

References NULL.

◆ assert() [2/7]

assert ( strcmp(SCIPheurGetName(heur), HEUR_NAME) = =0)

References HEUR_NAME.

◆ assert() [3/7]

assert ( scip ! = NULL)

References NULL.

◆ assert() [4/7]

assert ( heurdata ! = NULL)

References heurdata, and NULL.

◆ SCIPfreeBlockMemory()

SCIPfreeBlockMemory ( scip ,
& heurdata )

References heurdata.

◆ SCIPheurSetData()

SCIPheurSetData ( heur ,
NULL  )

References NULL.

◆ SCIPcreateSol()

SCIPcreateSol ( scip ,
&heurdata-> sol,
heur  )

References heurdata, and SCIP_OKAY.

◆ SCIPfreeSol()

SCIPfreeSol ( scip ,
&heurdata-> sol )

References heurdata, and SCIP_OKAY.

◆ assert() [5/7]

assert ( SCIPheurGetNDivesets(heur) ,
0  )

◆ assert() [6/7]

assert ( SCIPheurGetDivesets(heur) ! = NULL)

References diveset, and NULL.

◆ assert() [7/7]

assert ( diveset ! = NULL)

References diveset, and NULL.

◆ if()

if ( SCIPgetNBinVars(scip)+SCIPgetNIntVars(scip) = = 0)

returns a score for the given candidate – the best candidate maximizes the diving score

Definition at line 186 of file heur_pscostdiving.c.

References diveset, heurdata, result, SCIP_DIVECONTEXT_SINGLE, and SCIP_OKAY.

Variable Documentation

◆ heurdata

heurdata = SCIPheurGetData(heur)

Definition at line 121 of file heur_pscostdiving.c.

◆ SCIP_OKAY

return SCIP_OKAY

Definition at line 126 of file heur_pscostdiving.c.

◆ diveset

diveset
Initial value:
{
struct SCIP_HeurData SCIP_HEURDATA
Definition type_heur.h:77

execution method of primal heuristic

Definition at line 174 of file heur_pscostdiving.c.

◆ result

* result = SCIP_DIDNOTRUN

Definition at line 183 of file heur_pscostdiving.c.