branch_relpscost.h File Reference

Detailed Description

reliable pseudo costs branching rule

Author

Tobias Achterberg

The reliable pseudo costs branching rule uses the notion of pseudo costs to measure the expected gain in the dual bound when branching on a particular variable. The pseudo cost information is collected during the branch-and-bound search in the same manner as for the pseudo costs branching rule.

The reliable pseudo costs branching rule, however, uses a limited number of look-ahead LP-iterations at the beginning of the search in order to obtain better pseudo cost estimates and make branching decisions in a sense more "reliable" at an early stage of the search, at the price of a higher computational cost at the beginning of the search.

For a more mathematical description and a comparison between the reliable pseudo costs rule and other branching rules in SCIP, we refer to

Tobias Achterberg
Constraint Integer Programming
PhD Thesis, Technische Universität Berlin, 2007

Definition in file branch_relpscost.h.

#include "scip/scip.h"

Go to the source code of this file.

Functions
SCIP_RETCODE	SCIPincludeBranchruleRelpscost (SCIP *scip)
SCIP_RETCODE	SCIPexecRelpscostBranching (SCIP *scip, SCIP_Bool allowaddcons, SCIP_VAR **branchcands, SCIP_Real *branchcandssol, SCIP_Real *branchcandsfrac, int nbranchcands, SCIP_RESULT *result)

Function Documentation

SCIP_RETCODE SCIPincludeBranchruleRelpscost

(

SCIP *

scip

)

creates the reliable pseudo cost branching rule and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 1051 of file branch_relpscost.c.

References BRANCHRULE_DESC, BRANCHRULE_MAXBOUNDDIST, BRANCHRULE_MAXDEPTH, BRANCHRULE_NAME, BRANCHRULE_PRIORITY, DEFAULT_CONFLENGTHWEIGHT, DEFAULT_CONFLICTWEIGHT, DEFAULT_CUTOFFWEIGHT, DEFAULT_INFERENCEWEIGHT, DEFAULT_INITCAND, DEFAULT_INITITER, DEFAULT_MAXBDCHGS, DEFAULT_MAXLOOKAHEAD, DEFAULT_MAXPROPROUNDS, DEFAULT_MAXRELIABLE, DEFAULT_MINRELIABLE, DEFAULT_PROBINGBOUNDS, DEFAULT_PSCOSTWEIGHT, DEFAULT_SBITEROFS, DEFAULT_SBITERQUOT, FALSE, NULL, SCIP_CALL, SCIP_OKAY, SCIP_REAL_MAX, SCIP_REAL_MIN, SCIPaddBoolParam(), SCIPaddIntParam(), SCIPaddRealParam(), SCIPallocMemory, SCIPincludeBranchruleBasic(), SCIPsetBranchruleCopy(), SCIPsetBranchruleExecLp(), SCIPsetBranchruleFree(), and TRUE.

Referenced by SCIP_DECL_BRANCHCOPY(), and SCIPincludeDefaultPlugins().

SCIP_RETCODE SCIPexecRelpscostBranching	(	SCIP *	scip,
		SCIP_Bool	allowaddcons,
		SCIP_VAR **	branchcands,
		SCIP_Real *	branchcandssol,
		SCIP_Real *	branchcandsfrac,
		int	nbranchcands,
		SCIP_RESULT *	result
	)

execution reliability pseudo cost branching with the given branching candidates

Parameters

scip	SCIP data structure
allowaddcons	is the branching rule allowed to add constraints to the current node in order to cut off the current solution instead of creating a branching?
branchcands	branching candidates
branchcandssol	solution value for the branching candidates
branchcandsfrac	fractional part of the branching candidates
nbranchcands	number of branching candidates
result	pointer to the result of the execution

Definition at line 1139 of file branch_relpscost.c.

References BRANCHRULE_NAME, execRelpscost(), NULL, SCIP_CALL, SCIP_OKAY, and SCIPfindBranchrule().