Files
2008-04-15 18:56:58 +01:00

87 lines
2.3 KiB
C

/*
* coarsen.c
*
* This file contains the driving routines for the coarsening process
*
* Started 7/23/97
* George
*
* $Id: coarsen.c,v 1.2 2003/07/31 16:23:29 karypis Exp $
*
*/
#include <metis.h>
/*************************************************************************
* This function takes a graph and creates a sequence of coarser graphs
**************************************************************************/
GraphType *Coarsen2Way(CtrlType *ctrl, GraphType *graph)
{
int clevel;
GraphType *cgraph;
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->CoarsenTmr));
cgraph = graph;
/* The following is ahack to allow the multiple bisections to go through with correct
coarsening */
if (ctrl->CType > 20) {
clevel = 1;
ctrl->CType -= 20;
}
else
clevel = 0;
do {
IFSET(ctrl->dbglvl, DBG_COARSEN, printf("%6d %7d [%d] [%d %d]\n",
cgraph->nvtxs, cgraph->nedges, ctrl->CoarsenTo, ctrl->maxvwgt,
(cgraph->vwgt ? idxsum(cgraph->nvtxs, cgraph->vwgt) : cgraph->nvtxs)));
if (cgraph->adjwgt) {
switch (ctrl->CType) {
case MATCH_RM:
Match_RM(ctrl, cgraph);
break;
case MATCH_HEM:
if (clevel < 1 || cgraph->nedges == 0)
Match_RM(ctrl, cgraph);
else
Match_HEM(ctrl, cgraph);
break;
case MATCH_SHEM:
if (clevel < 1 || cgraph->nedges == 0)
Match_RM(ctrl, cgraph);
else
Match_SHEM(ctrl, cgraph);
break;
case MATCH_SHEMKWAY:
if (cgraph->nedges == 0)
Match_RM(ctrl, cgraph);
else
Match_SHEM(ctrl, cgraph);
break;
default:
errexit("Unknown CType: %d\n", ctrl->CType);
}
}
else {
Match_RM_NVW(ctrl, cgraph);
}
cgraph = cgraph->coarser;
clevel++;
} while (cgraph->nvtxs > ctrl->CoarsenTo && cgraph->nvtxs < COARSEN_FRACTION2*cgraph->finer->nvtxs && cgraph->nedges > cgraph->nvtxs/2);
IFSET(ctrl->dbglvl, DBG_COARSEN, printf("%6d %7d [%d] [%d %d]\n",
cgraph->nvtxs, cgraph->nedges, ctrl->CoarsenTo, ctrl->maxvwgt,
(cgraph->vwgt ? idxsum(cgraph->nvtxs, cgraph->vwgt) : cgraph->nvtxs)));
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->CoarsenTmr));
return cgraph;
}