/*************************************************************************
* This function takes a graph and produces a bisection of it
**************************************************************************/
void MlevelNestedDissection(CtrlType *ctrl, GraphType *graph, idxtype *order, float ubfactor, int lastvtx)
{
int i, j, nvtxs, nbnd, tvwgt, tpwgts2[2];
idxtype *label, *bndind;
GraphType lgraph, rgraph;
nvtxs = graph->nvtxs;
/* Determine the weights of the partitions */
tvwgt = idxsum(nvtxs, graph->vwgt);
tpwgts2[0] = tvwgt/2;
tpwgts2[1] = tvwgt-tpwgts2[0];
switch (ctrl->optype) {
case OP_OEMETIS:
MlevelEdgeBisection(ctrl, graph, tpwgts2, ubfactor);
IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->SepTmr));
ConstructMinCoverSeparator(ctrl, graph, ubfactor);
IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->SepTmr));
break;
case OP_ONMETIS:
MlevelNodeBisectionMultiple(ctrl, graph, tpwgts2, ubfactor);
IFSET(ctrl->dbglvl, DBG_SEPINFO, printf("Nvtxs: %6d, [%6d %6d %6d]\n", graph->nvtxs, graph->pwgts[0], graph->pwgts[1], graph->pwgts[2]));
break;
}
/* Order the nodes in the separator */
nbnd = graph->nbnd;
bndind = graph->bndind;
label = graph->label;
for (i=0; i<nbnd; i++)
order[label[bndind[i]]] = --lastvtx;
SplitGraphOrder(ctrl, graph, &lgraph, &rgraph);
/* Free the memory of the top level graph */
/*GKfree(&graph->gdata, &graph->rdata, &graph->label, LTERM);*/
GKfree3((void **)&graph->gdata, (void**)&graph->rdata, (void **)&graph->label);
if (rgraph.nvtxs > MMDSWITCH)
MlevelNestedDissection(ctrl, &rgraph, order, ubfactor, lastvtx);
else {
MMDOrder(ctrl, &rgraph, order, lastvtx);
/*GKfree(&rgraph.gdata, &rgraph.rdata, &rgraph.label, LTERM);*/
GKfree3((void**)&rgraph.gdata, (void**)&rgraph.rdata, (void**)&rgraph.label);
}
if (lgraph.nvtxs > MMDSWITCH)
MlevelNestedDissection(ctrl, &lgraph, order, ubfactor, lastvtx-rgraph.nvtxs);
else {
MMDOrder(ctrl, &lgraph, order, lastvtx-rgraph.nvtxs);
/*GKfree(&lgraph.gdata, &lgraph.rdata, &lgraph.label, LTERM);*/
GKfree3((void**)&lgraph.gdata, (void**)&lgraph.rdata, (void**)&lgraph.label);
}
}
/*************************************************************************
* This function is the entry point for ONWMETIS. It requires weights on the
* vertices. It is for the case that the matrix has been pre-compressed.
**************************************************************************/
void METIS_EdgeComputeSeparator(int *nvtxs, idxtype *xadj, idxtype *adjncy, idxtype *vwgt,
idxtype *adjwgt, int *options, int *sepsize, idxtype *part)
{
int i, j, tvwgt, tpwgts[2];
GraphType graph;
CtrlType ctrl;
SetUpGraph(&graph, OP_ONMETIS, *nvtxs, 1, xadj, adjncy, vwgt, adjwgt, 3);
tvwgt = idxsum(*nvtxs, graph.vwgt);
if (options[0] == 0) { /* Use the default parameters */
ctrl.CType = ONMETIS_CTYPE;
ctrl.IType = ONMETIS_ITYPE;
ctrl.RType = ONMETIS_RTYPE;
ctrl.dbglvl = ONMETIS_DBGLVL;
}
else {
ctrl.CType = options[OPTION_CTYPE];
ctrl.IType = options[OPTION_ITYPE];
ctrl.RType = options[OPTION_RTYPE];
ctrl.dbglvl = options[OPTION_DBGLVL];
}
ctrl.oflags = 0;
ctrl.pfactor = 0;
ctrl.nseps = 5;
ctrl.optype = OP_OEMETIS;
ctrl.CoarsenTo = amin(100, *nvtxs-1);
ctrl.maxvwgt = 1.5*tvwgt/ctrl.CoarsenTo;
InitRandom(options[7]);
AllocateWorkSpace(&ctrl, &graph, 2);
/*============================================================
* Perform the bisection
*============================================================*/
tpwgts[0] = tvwgt/2;
tpwgts[1] = tvwgt-tpwgts[0];
MlevelEdgeBisection(&ctrl, &graph, tpwgts, 1.05);
ConstructMinCoverSeparator(&ctrl, &graph, 1.05);
*sepsize = graph.pwgts[2];
idxcopy(*nvtxs, graph.where, part);
GKfree((void**)&graph.gdata, &graph.rdata, &graph.label, LTERM);
FreeWorkSpace(&ctrl, &graph);
}
