Detailed Description

shortest paths based primal heuristics for Steiner problems

Author: Gerald Gamrath; Thorsten Koch; Daniel Rehfeldt; Michael Winkler

This file implements several shortest paths based primal heuristics for Steiner problems, see "SCIP-Jack - A solver for STP and variants with parallelization extensions" by Gamrath, Koch, Maher, Rehfeldt and Shinano

Definition in file heur_tm.h.

#include "scip/scip.h"
#include "graph.h"

Go to the source code of this file.

Macros
#define	DEFAULT_HOPFACTOR 0.33

Enumerations
enum	PCMW_TmMode { pcmode_simple = 0, pcmode_bias = 1, pcmode_biasfull = 2, pcmode_fulltree = 3, pcmode_all = 4, pcmode_biasAndFulltree = 5, pcmode_fromheurdata = 6 }

Functions
void	SCIPStpHeurTMCompStarts (GRAPH graph, int starts, int *runs)

SCIP_RETCODE	SCIPStpIncludeHeurTM (SCIP *scip)

SCIP_RETCODE	SCIPStpHeurTMRun (SCIP scip, enum PCMW_TmMode pcmw_tmmode, GRAPH graph, int starts, const SCIP_Real prize, int best_result, int runs, int bestincstart, SCIP_Real cost, SCIP_Real costrev, SCIP_Real hopfactor, SCIP_Real nodepriority, SCIP_Bool success)

SCIP_RETCODE	SCIPStpHeurTMRunLP (SCIP scip, GRAPH graph, SCIP_HEUR heur, int result, int runs, SCIP_Bool *success)

SCIP_RETCODE	SCIPStpHeurTMBuildTreePcMw (SCIP scip, const GRAPH g, SCIP_Bool useRootSym, PATH mst, const SCIP_Real cost, SCIP_Real objresult, int connected)

void	SCIPStpHeurTMBuildTree (SCIP scip, GRAPH g, PATH mst, const SCIP_Real cost, SCIP_Real objresult, int connected)

SCIP_RETCODE	SCIPStpHeurTMBuildTreeDc (SCIP scip, const GRAPH g, int result, STP_Bool connected)

Macro Definition Documentation

◆ DEFAULT_HOPFACTOR

#define DEFAULT_HOPFACTOR 0.33

Definition at line 42 of file heur_tm.h.

Referenced by dhcstpWarmUp(), reduce_boundHopRc(), and SCIPStpIncludeHeurTM().

Enumeration Type Documentation

◆ PCMW_TmMode

enum PCMW_TmMode

TM mode for PC/MW NOTE: bias_simple is only used for PC/RPC

Enumerator
pcmode_simple
pcmode_bias
pcmode_biasfull
pcmode_fulltree
pcmode_all
pcmode_biasAndFulltree
pcmode_fromheurdata

Definition at line 47 of file heur_tm.h.

Function Documentation

◆ SCIPStpHeurTMCompStarts()

void SCIPStpHeurTMCompStarts	(	GRAPH *	graph,
		int *	starts,
		int *	runs
	)

compute starting points among marked (w.r.t. g->mark) vertices for constructive heuristics

Parameters

graph	graph data structure
starts	starting points array
runs	pointer to number of runs

Definition at line 2879 of file heur_tm.c.

References Is_term, GRAPH::knots, GRAPH::mark, nnodes, TM_base_data::nruns, nterms, NULL, r, GRAPH::source, GRAPH::term, and GRAPH::terms.

Referenced by computeNewSols(), computeSteinerTree(), computeSteinerTreeTM(), redcostGraphComputeSteinerTreeDirected(), and updateSolution().

◆ SCIPStpIncludeHeurTM()

SCIP_RETCODE SCIPStpIncludeHeurTM ( SCIP * scip )

creates the TM primal heuristic and includes it in SCIP

Parameters

scip	SCIP data structure

Definition at line 3711 of file heur_tm.c.

References DEFAULT_DURINGLPFREQ, DEFAULT_EVALRUNS, DEFAULT_HARD_RUNSMULT, DEFAULT_HOPFACTOR, DEFAULT_INITRUNS, DEFAULT_LEAFRUNS, DEFAULT_PCMODE, DEFAULT_RANDSEED, DEFAULT_ROOTRUNS, DEFAULT_TYPE, FALSE, HEUR_DESC, HEUR_DISPCHAR, HEUR_FREQ, HEUR_FREQOFS, HEUR_MAXDEPTH, HEUR_NAME, HEUR_PRIORITY, HEUR_TIMING, HEUR_USESSUBSCIP, NULL, SCIP_CALL, SCIP_HEURTIMING_AFTERLPLOOP, SCIP_HEURTIMING_AFTERNODE, SCIP_HEURTIMING_AFTERPSEUDONODE, SCIP_HEURTIMING_BEFORENODE, SCIP_HEURTIMING_DURINGLPLOOP, SCIP_MAXSTRLEN, SCIP_OKAY, SCIPaddIntParam(), SCIPaddRealParam(), SCIPallocMemory, SCIPcreateRandom(), SCIPincludeHeurBasic(), SCIPsetHeurCopy(), SCIPsetHeurFree(), SCIPsetHeurInit(), SCIPsnprintf(), and TRUE.

Referenced by runShell(), SCIP_DECL_HEURCOPY(), and subscipSetupCallbacks().

◆ SCIPStpHeurTMRun()

SCIP_RETCODE SCIPStpHeurTMRun	(	SCIP *	scip,
		enum PCMW_TmMode	pcmw_tmmode,
		GRAPH *	graph,
		int *	starts,
		const SCIP_Real *	prize,
		int *	best_result,
		int	runs,
		int	bestincstart,
		SCIP_Real *	cost,
		SCIP_Real *	costrev,
		SCIP_Real *	hopfactor,
		SCIP_Real *	nodepriority,
		SCIP_Bool *	success
	)

execute shortest paths heuristic to obtain a Steiner tree

Parameters

scip	SCIP data structure
pcmw_tmmode	mode for PC/MW
graph	graph data structure
starts	array containing start vertices (NULL to not provide any)
prize	prizes (for PCMW) or NULL
best_result	array indicating whether an arc is part of the solution (CONNECTED/UNKNOWN)
runs	number of runs
bestincstart	best incumbent start vertex
cost	arc costs
costrev	reversed arc costs
hopfactor	edge cost multiplicator for HC problems
nodepriority	vertex priorities for vertices to be starting points (NULL for no priorities)
success	pointer to store whether a solution could be found

Definition at line 3418 of file heur_tm.c.

References TM_base_data::best_result, computeStarts(), TM_base_data::cost, TM_base_data::costrev, TM_base_data::dheap, FALSE, FARAWAY, getTMheurData(), getTmMode(), graph_get_nEdges(), graph_pc_2transcheck(), graph_pc_isPcMw(), graph_printInfoReduced(), NULL, runTm(), runTmDhcstp(), runTmPcMW(), SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPdebugMessage, SCIPisGE(), solstp_getObj(), GRAPH::source, STP_DHCSTP, GRAPH::stp_type, TM_SP, TM_VORONOI, tmAllspFree(), tmAllspInit(), tmBaseFree(), tmBaseInit(), tmVnoiFree(), and tmVnoiInit().

Referenced by computeNewSols(), computeReducedProbSolutionBiased(), computeSteinerTree(), computeSteinerTreeTM(), createInitialCuts(), daPcAddTmSolToPool(), redcostGraphComputeSteinerTreeDegCons(), redcostGraphComputeSteinerTreeDirected(), reduce_boundHopRc(), runTmPcFull(), SCIPStpHeurRecExclude(), SCIPStpHeurTMRunLP(), and updateSolution().

◆ SCIPStpHeurTMRunLP()

SCIP_RETCODE SCIPStpHeurTMRunLP	(	SCIP *	scip,
		GRAPH *	graph,
		SCIP_HEUR *	heur,
		int *	result,
		int	runs,
		SCIP_Bool *	success
	)

run shortest path heuristic, but bias edge costs towards best current LP solution

Parameters

scip	SCIP data structure
graph	graph data structure
heur	heuristic or NULL
result	(uninitialized) array indicating whether an arc is part of the solution (CONNECTED/UNKNOWN)
runs	number of runs
success	pointer to store whether a solution could be found

Definition at line 3509 of file heur_tm.c.

References BLOCKED, BMScopyMemoryArray, TM_base_data::cost, GRAPH::cost, TM_base_data::costrev, eps, FALSE, flipedge_Uint, getTmEdgeCostZeroOffset(), GRAPH::grad, graph_get_nEdges(), graph_get_nNodes(), graph_knot_chg(), graph_pc_isPcMw(), graph_typeIsSpgLike(), GRAPH::head, initCostsAndPrioLP(), Is_term, LE, MAX, nnodes, NULL, pcmode_bias, SCIP_Bool, SCIP_CALL, SCIP_LPSOLSTAT_OPTIMAL, SCIP_OKAY, SCIP_Real, SCIPallocBufferArray, SCIPcreateSol(), SCIPepsilon(), SCIPfindHeur(), SCIPfreeBufferArray, SCIPfreeBufferArrayNull, SCIPfreeSol(), SCIPgetLPSolstat(), SCIPhasCurrentNodeLP(), SCIPheurGetData(), SCIPisZero(), SCIPlinkLPSol(), SCIPprobdataGetVars(), SCIPprobdataGetXval(), SCIPrandomGetReal(), SCIPStpHeurTMRun(), SCIPvarGetUbGlobal(), solstp_addSolToProb(), solstp_pruneFromEdges(), GRAPH::source, STP_BRMWCSP, STP_DHCSTP, STP_TERM, GRAPH::stp_type, GRAPH::term, and UNKNOWN.

Referenced by SCIP_DECL_HEUREXEC(), and selectBranchingVertexBySol().

◆ SCIPStpHeurTMBuildTreePcMw()

SCIP_RETCODE SCIPStpHeurTMBuildTreePcMw	(	SCIP *	scip,
		const GRAPH *	g,
		SCIP_Bool	useRootSym,
		PATH *	mst,
		const SCIP_Real *	cost,
		SCIP_Real *	objresult,
		int *	connected
	)

build (rooted) prize collecting Steiner tree in such a way that all leaves are positive-weight vertices

build (rooted) prize collecting Steiner tree in such a way that all leaves are terminals; objresult is set FARAWAY if infeasible

Parameters

scip	SCIP data structure
g	graph structure
useRootSym	use?
mst	path data structure array
cost	edge costs
objresult	pointer to store objective value of result
connected	CONNECT/UNKNOWN

Definition at line 3012 of file heur_tm.c.

References a, CONNECT, EAT_LAST, shortest_path::edge, GRAPH::extended, FALSE, FARAWAY, graph_path_exec(), graph_pc_isRootedPcMw(), graph_pc_isUnrootedPcMw(), graph_pc_knotIsDummyTerm(), graph_pc_knotIsFixedTerm(), GRAPH::head, GRAPH::ieat, GRAPH::inpbeg, Is_pseudoTerm, Is_term, GRAPH::knots, GRAPH::mark, MST_MODE, nnodes, NULL, GRAPH::oeat, GRAPH::outbeg, GRAPH::path_state, SCIP_Bool, SCIP_OKAY, SCIP_Real, SCIPdebugMessage, SCIPprobdataGetNNodes(), SCIPprobdataGetNTerms(), SCIPprobdataGetPctermsorder(), GRAPH::source, GRAPH::tail, GRAPH::term, GRAPH::terms, TRUE, and UNKNOWN.

Referenced by nodesolUpdate(), and SCIPStpHeurPruneUpdateSols().

◆ SCIPStpHeurTMBuildTree()

void SCIPStpHeurTMBuildTree	(	SCIP *	scip,
		GRAPH *	g,
		PATH *	mst,
		const SCIP_Real *	cost,
		SCIP_Real *	objresult,
		int *	connected
	)

build Steiner tree in such a way that all leaves are terminals

Parameters

scip	SCIP data structure
g	graph structure
mst	path data structure array
cost	edge costs
objresult	pointer to store objective value of result
connected	CONNECT/UNKNOWN

Definition at line 2932 of file heur_tm.c.

References CONNECT, EAT_LAST, shortest_path::edge, FALSE, FARAWAY, graph_path_exec(), graph_pc_isPcMw(), GRAPH::head, Is_term, GRAPH::knots, GRAPH::mark, MST_MODE, nnodes, NULL, GRAPH::oeat, GRAPH::outbeg, SCIP_Real, GRAPH::source, GRAPH::term, and UNKNOWN.

Referenced by nodesolUpdate(), and SCIPStpHeurPruneUpdateSols().

◆ SCIPStpHeurTMBuildTreeDc()

SCIP_RETCODE SCIPStpHeurTMBuildTreeDc	(	SCIP *	scip,
		const GRAPH *	g,
		int *	result,
		STP_Bool *	connected
	)

prune a degree constrained Steiner tree in such a way that all leaves are terminals

Parameters

scip	SCIP data structure
g	graph structure
result	ST edges
connected	ST nodes (to be set)

Definition at line 3226 of file heur_tm.c.

References CONNECT, GRAPH::cost, EAT_LAST, FALSE, flipedge, GRAPH::head, GRAPH::ieat, GRAPH::inpbeg, Is_term, GRAPH::knots, LT, GRAPH::maxdeg, nnodes, NULL, GRAPH::oeat, GRAPH::outbeg, SCIP_Bool, SCIP_CALL, SCIP_OKAY, SCIPallocBufferArray, SCIPdebug, SCIPfreeBufferArray, GRAPH::source, GRAPH::term, TRUE, and UNKNOWN.

Referenced by computeDegConsTree(), and SCIPStpHeurRecRun().

SCIP

Detailed Description

Macros

Enumerations

Functions

Macro Definition Documentation

◆ DEFAULT_HOPFACTOR

Enumeration Type Documentation

◆ PCMW_TmMode

Function Documentation

◆ SCIPStpHeurTMCompStarts()

◆ SCIPStpIncludeHeurTM()

◆ SCIPStpHeurTMRun()

◆ SCIPStpHeurTMRunLP()

◆ SCIPStpHeurTMBuildTreePcMw()

◆ SCIPStpHeurTMBuildTree()

◆ SCIPStpHeurTMBuildTreeDc()