Scippy

SCIP

Solving Constraint Integer Programs

prop_stp.h File Reference

Detailed Description

propagator for Steiner tree problems, using the LP reduced costs

Author
Daniel Rehfeldt

This propagator makes use of the reduced cost of an optimally solved LP relaxation to propagate the variables, see "SCIP-Jack - A solver for STP and variants with parallelization extensions" by Gamrath, Koch, Maher, Rehfeldt and Shinano

Definition in file prop_stp.h.

#include <stdio.h>
#include <stdlib.h>
#include "scip/scip.h"
#include "grph.h"
#include "probdata_stp.h"

Go to the source code of this file.

Functions

SCIP_EXPORT SCIP_RETCODE SCIPincludePropStp (SCIP *scip)
 
SCIP_EXPORT SCIP_RETCODE fixedgevar (SCIP *scip, SCIP_VAR *edgevar, int *nfixed)
 
SCIP_EXPORT int SCIPStpNfixedEdges (SCIP *scip)
 
SCIP_EXPORT void SCIPStpPropGetGraph (SCIP *scip, GRAPH **graph, SCIP_Longint *graphnodenumber)
 

Function Documentation

◆ SCIPincludePropStp()

SCIP_EXPORT SCIP_RETCODE SCIPincludePropStp ( SCIP scip)

◆ fixedgevar()

SCIP_EXPORT SCIP_RETCODE fixedgevar ( SCIP scip,
SCIP_VAR edgevar,
int *  nfixed 
)

fix a variable (corresponding to an edge) to zero

Parameters
scipSCIP data structure
edgevarthe variable to be fixed
nfixedcounter that is incriminated if variable could be fixed

Definition at line 848 of file prop_stp.c.

References NULL, SCIP_CALL, SCIP_OKAY, SCIPchgVarUb(), SCIPvarGetLbLocal(), and SCIPvarGetUbLocal().

Referenced by dualcostVarfixing(), redbasedVarfixing(), and reduce_boundHopRc().

◆ SCIPStpNfixedEdges()

SCIP_EXPORT int SCIPStpNfixedEdges ( SCIP scip)

return total number of arcs fixed by 'fixedgevar' method of this propagator

Parameters
scipSCIP data structure

Definition at line 865 of file prop_stp.c.

References NULL, SCIPfindProp(), and SCIPpropGetData().

Referenced by SCIP_DECL_HEUREXEC().

◆ SCIPStpPropGetGraph()

SCIP_EXPORT void SCIPStpPropGetGraph ( SCIP scip,
GRAPH **  graph,
SCIP_Longint graphnodenumber 
)

gets propagator graph

Parameters
scipSCIP data structure
graphgraph data
graphnodenumberpoint to b&b node for which graph is valid

Definition at line 883 of file prop_stp.c.

References NULL, SCIPfindProp(), and SCIPpropGetData().