heur_proximity.h File Reference

Detailed Description

improvement heuristic which uses an auxiliary objective instead of the original objective function which is itself added as a constraint to a sub-SCIP instance. The heuristic was presented by Matteo Fischetti and Michele Monaci

Author

Gregor Hendel

Definition in file heur_proximity.h.

#include "scip/scip.h"

Go to the source code of this file.

Functions
SCIP_RETCODE	SCIPapplyProximity (SCIP *scip, SCIP_HEUR *heur, SCIP_RESULT *result, SCIP_Real minimprove, SCIP_Longint nnodes, SCIP_Longint nlpiters, SCIP_Longint *nusednodes, SCIP_Longint *nusedlpiters, SCIP_Bool freesubscip)
SCIP_RETCODE	SCIPincludeHeurProximity (SCIP *scip)
SCIP_RETCODE	SCIPdeleteSubproblemProximity (SCIP *scip)

Function Documentation

SCIP_RETCODE SCIPapplyProximity	(	SCIP *	scip,
		SCIP_HEUR *	heur,
		SCIP_RESULT *	result,
		SCIP_Real	minimprove,
		SCIP_Longint	nnodes,
		SCIP_Longint	nlpiters,
		SCIP_Longint *	nusednodes,
		SCIP_Longint *	nusedlpiters,
		SCIP_Bool	freesubscip
	)

main procedure of the proximity heuristic, creates and solves a sub-SCIP

Note

the method can be applied in an iterative way, keeping the same subscip in between. If the freesubscip parameter is set to FALSE, the heuristic will keep the subscip data structures. Always set this parameter to TRUE, or call SCIPdeleteSubproblemProximity() afterwards

Parameters

scip	original SCIP data structure
heur	heuristic data structure
result	result data structure
minimprove	factor by which proximity should at least improve the incumbent
nnodes	node limit for the subproblem
nlpiters	LP iteration limit for the subproblem
nusednodes	pointer to store number of used nodes in subscip
nusedlpiters	pointer to store number of used LP iterations in subscip
freesubscip	should the created sub-MIP be freed at the end of the method?

SCIP_RETCODE SCIPincludeHeurProximity

(

SCIP *

scip

)

creates the proximity primal heuristic and includes it in SCIP

Parameters

scip	SCIP data structure

SCIP_RETCODE SCIPdeleteSubproblemProximity

(

SCIP *

scip

)

frees the sub-MIP created by proximity

Parameters

scip	SCIP data structure