openfoam/applications/utilities/parallelProcessing/decompositionMethods/metis-5.0pre2/libmetis/kmetis.c
2008-04-15 18:56:58 +01:00

128 lines
4.1 KiB
C

/*
* Copyright 1997, Regents of the University of Minnesota
*
* kmetis.c
*
* This file contains the top level routines for the multilevel k-way partitioning
* algorithm KMETIS.
*
* Started 7/28/97
* George
*
*/
#include <metislib.h>
/*************************************************************************
* This function is the entry point for KMETIS
**************************************************************************/
void METIS_PartGraphKway(idxtype *nvtxs, idxtype *xadj, idxtype *adjncy, idxtype *vwgt,
idxtype *adjwgt, idxtype *wgtflag, idxtype *numflag, idxtype *nparts,
idxtype *options, idxtype *edgecut, idxtype *part)
{
idxtype i;
float *tpwgts;
tpwgts = gk_fmalloc(*nparts, "KMETIS: tpwgts");
for (i=0; i<*nparts; i++)
tpwgts[i] = 1.0/(1.0*(*nparts));
METIS_WPartGraphKway(nvtxs, xadj, adjncy, vwgt, adjwgt, wgtflag, numflag, nparts,
tpwgts, options, edgecut, part);
gk_free((void **)&tpwgts, LTERM);
}
/*************************************************************************
* This function is the entry point for KWMETIS
**************************************************************************/
void METIS_WPartGraphKway(idxtype *nvtxs, idxtype *xadj, idxtype *adjncy, idxtype *vwgt,
idxtype *adjwgt, idxtype *wgtflag, idxtype *numflag, idxtype *nparts,
float *tpwgts, idxtype *options, idxtype *edgecut, idxtype *part)
{
idxtype i, j;
GraphType graph;
CtrlType ctrl;
if (*numflag == 1)
Change2CNumbering(*nvtxs, xadj, adjncy);
SetUpGraph(&graph, OP_KMETIS, *nvtxs, 1, xadj, adjncy, vwgt, adjwgt, *wgtflag);
if (options[0] == 0) { /* Use the default parameters */
ctrl.CType = KMETIS_CTYPE;
ctrl.IType = KMETIS_ITYPE;
ctrl.RType = KMETIS_RTYPE;
ctrl.dbglvl = KMETIS_DBGLVL;
}
else {
ctrl.CType = options[OPTION_CTYPE];
ctrl.IType = options[OPTION_ITYPE];
ctrl.RType = options[OPTION_RTYPE];
ctrl.dbglvl = options[OPTION_DBGLVL];
}
ctrl.optype = OP_KMETIS;
ctrl.CoarsenTo = amax((*nvtxs)/(40*gk_log2(*nparts)), 20*(*nparts));
ctrl.maxvwgt = 1.5*((graph.vwgt ? idxsum(*nvtxs, graph.vwgt, 1) : (*nvtxs))/ctrl.CoarsenTo);
InitRandom(-1);
AllocateWorkSpace(&ctrl, &graph, *nparts);
IFSET(ctrl.dbglvl, DBG_TIME, InitTimers(&ctrl));
IFSET(ctrl.dbglvl, DBG_TIME, gk_startcputimer(ctrl.TotalTmr));
*edgecut = MlevelKWayPartitioning(&ctrl, &graph, *nparts, part, tpwgts, 1.03);
IFSET(ctrl.dbglvl, DBG_TIME, gk_stopcputimer(ctrl.TotalTmr));
IFSET(ctrl.dbglvl, DBG_TIME, PrintTimers(&ctrl));
FreeWorkSpace(&ctrl, &graph);
if (*numflag == 1)
Change2FNumbering(*nvtxs, xadj, adjncy, part);
}
/*************************************************************************
* This function takes a graph and produces a bisection of it
**************************************************************************/
idxtype MlevelKWayPartitioning(CtrlType *ctrl, GraphType *graph, idxtype nparts, idxtype *part, float *tpwgts, float ubfactor)
{
idxtype i, j, nvtxs, tvwgt, tpwgts2[2];
GraphType *cgraph;
idxtype wgtflag=3, numflag=0, options[10], edgecut;
cgraph = Coarsen2Way(ctrl, graph);
IFSET(ctrl->dbglvl, DBG_TIME, gk_startcputimer(ctrl->InitPartTmr));
AllocateKWayPartitionMemory(ctrl, cgraph, nparts);
options[0] = 1;
options[OPTION_CTYPE] = MTYPE_SHEMKWAY;
options[OPTION_ITYPE] = ITYPE_GGPKL;
options[OPTION_RTYPE] = RTYPE_FM;
options[OPTION_DBGLVL] = 0;
METIS_WPartGraphRecursive(&cgraph->nvtxs, cgraph->xadj, cgraph->adjncy, cgraph->vwgt,
cgraph->adjwgt, &wgtflag, &numflag, &nparts, tpwgts, options,
&edgecut, cgraph->where);
IFSET(ctrl->dbglvl, DBG_TIME, gk_stopcputimer(ctrl->InitPartTmr));
IFSET(ctrl->dbglvl, DBG_IPART, mprintf("Initial %D-way partitioning cut: %D\n", nparts, edgecut));
IFSET(ctrl->dbglvl, DBG_KWAYPINFO, ComputePartitionInfo(cgraph, nparts, cgraph->where));
RefineKWay(ctrl, graph, cgraph, nparts, tpwgts, ubfactor);
idxcopy(graph->nvtxs, graph->where, part);
FreeGraph(graph, 0);
return graph->mincut;
}