Esempio n. 1
0
/*************************************************************************
* This function takes a graph and produces a bisection of it
**************************************************************************/
int MCMlevelKWayPartitioning(CtrlType *ctrl, GraphType *graph, int nparts, idxtype *part, 
      float *rubvec)
{
  int i, j, nvtxs;
  GraphType *cgraph;
  int options[10], edgecut;

  cgraph = MCCoarsen2Way(ctrl, graph);

  IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->InitPartTmr));
  MocAllocateKWayPartitionMemory(ctrl, cgraph, nparts);

  options[0] = 1; 
  options[OPTION_CTYPE] = MATCH_SBHEM_INFNORM;
  options[OPTION_ITYPE] = IPART_RANDOM;
  options[OPTION_RTYPE] = RTYPE_FM;
  options[OPTION_DBGLVL] = 0;

  /* Determine what you will use as the initial partitioner, based on tolerances */
  for (i=0; i<graph->ncon; i++) {
    if (rubvec[i] > 1.2)
      break;
  }
  if (i == graph->ncon)
    METIS_mCPartGraphRecursiveInternal(&cgraph->nvtxs, &cgraph->ncon, 
          cgraph->xadj, cgraph->adjncy, cgraph->nvwgt, cgraph->adjwgt, &nparts, 
          options, &edgecut, cgraph->where);
  else
    METIS_mCHPartGraphRecursiveInternal(&cgraph->nvtxs, &cgraph->ncon, 
          cgraph->xadj, cgraph->adjncy, cgraph->nvwgt, cgraph->adjwgt, &nparts, 
          rubvec, options, &edgecut, cgraph->where);


  IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->InitPartTmr));
  IFSET(ctrl->dbglvl, DBG_IPART, printf("Initial %d-way partitioning cut: %d\n", nparts, edgecut));

  IFSET(ctrl->dbglvl, DBG_KWAYPINFO, ComputePartitionInfo(cgraph, nparts, cgraph->where));

  MocRefineKWayHorizontal(ctrl, graph, cgraph, nparts, rubvec);

  idxcopy(graph->nvtxs, graph->where, part);

  GKfree(&graph->nvwgt, &graph->npwgts, &graph->gdata, &graph->rdata, LTERM);

  return graph->mincut;

}
Esempio n. 2
0
/*************************************************************************
* This function projects a partition, and at the same time computes the
* parameters for refinement.
**************************************************************************/
void MocProjectKWayPartition(CtrlType *ctrl, GraphType *graph, int nparts)
{
  int i, j, k, nvtxs, nbnd, me, other, istart, iend, ndegrees;
  idxtype *xadj, *adjncy, *adjwgt, *adjwgtsum;
  idxtype *cmap, *where, *bndptr, *bndind;
  idxtype *cwhere;
  GraphType *cgraph;
  RInfoType *crinfo, *rinfo, *myrinfo;
  EDegreeType *myedegrees;
  idxtype *htable;

  cgraph = graph->coarser;
  cwhere = cgraph->where;
  crinfo = cgraph->rinfo;

  nvtxs = graph->nvtxs;
  cmap = graph->cmap;
  xadj = graph->xadj;
  adjncy = graph->adjncy;
  adjwgt = graph->adjwgt;
  adjwgtsum = graph->adjwgtsum;

  MocAllocateKWayPartitionMemory(ctrl, graph, nparts);
  where = graph->where;
  rinfo = graph->rinfo;
  bndind = graph->bndind;
  bndptr = idxset(nvtxs, -1, graph->bndptr);

  /* Go through and project partition and compute id/ed for the nodes */
  for (i=0; i<nvtxs; i++) {
    k = cmap[i];
    where[i] = cwhere[k];
    cmap[i] = crinfo[k].ed;  /* For optimization */
  }

  htable = idxset(nparts, -1, idxwspacemalloc(ctrl, nparts));

  ctrl->wspace.cdegree = 0;
  for (nbnd=0, i=0; i<nvtxs; i++) {
    me = where[i];

    myrinfo = rinfo+i;
    myrinfo->id = myrinfo->ed = myrinfo->ndegrees = 0;
    myrinfo->edegrees = NULL;

    myrinfo->id = adjwgtsum[i];

    if (cmap[i] > 0) { /* If it is an interface node. Note cmap[i] = crinfo[cmap[i]].ed */
      istart = xadj[i];
      iend = xadj[i+1];

      myedegrees = myrinfo->edegrees = ctrl->wspace.edegrees+ctrl->wspace.cdegree;
      ctrl->wspace.cdegree += iend-istart;

      ndegrees = 0;
      for (j=istart; j<iend; j++) {
        other = where[adjncy[j]];
        if (me != other) {
          myrinfo->ed += adjwgt[j];
          if ((k = htable[other]) == -1) {
            htable[other] = ndegrees;
            myedegrees[ndegrees].pid = other;
            myedegrees[ndegrees++].ed = adjwgt[j];
          }
          else {
            myedegrees[k].ed += adjwgt[j];
          }
        }
      }
      myrinfo->id -= myrinfo->ed;

      /* Remove space for edegrees if it was interior */
      if (myrinfo->ed == 0) { 
        myrinfo->edegrees = NULL;
        ctrl->wspace.cdegree -= iend-istart;
      }
      else {
        if (myrinfo->ed-myrinfo->id >= 0) 
          BNDInsert(nbnd, bndind, bndptr, i); 

        myrinfo->ndegrees = ndegrees;

        for (j=0; j<ndegrees; j++)
          htable[myedegrees[j].pid] = -1;
      }
    }
  }

  scopy(graph->ncon*nparts, cgraph->npwgts, graph->npwgts);
  graph->mincut = cgraph->mincut;
  graph->nbnd = nbnd;

  FreeGraph(graph->coarser);
  graph->coarser = NULL;

  idxwspacefree(ctrl, nparts);

  ASSERT(CheckBnd2(graph));

}