示例#1
0
void METIS_NodeRefine(int nvtxs, idxtype *xadj, idxtype *vwgt, idxtype *adjncy, 
           idxtype *adjwgt, idxtype *where, idxtype *hmarker, float ubfactor)
{
  GraphType *graph;
  CtrlType ctrl;

  ctrl.dbglvl    = ONMETIS_DBGLVL;
  ctrl.optype    = OP_ONMETIS;

  graph = CreateGraph();
  SetUpGraph(graph, OP_ONMETIS, nvtxs, 1, xadj, adjncy, vwgt, adjwgt, 3);

  AllocateWorkSpace(&ctrl, graph, 2);

  Allocate2WayNodePartitionMemory(&ctrl, graph);
  idxcopy(nvtxs, where, graph->where);

  Compute2WayNodePartitionParams(&ctrl, graph);

  FM_2WayNodeRefine_OneSidedP(&ctrl, graph, hmarker, ubfactor, 10); 
  /* FM_2WayNodeRefine_TwoSidedP(&ctrl, graph, hmarker, ubfactor, 10); */

  FreeWorkSpace(&ctrl, graph);

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

  FreeGraph(graph);

}
示例#2
0
/*************************************************************************
* This function takes a bisection and constructs a minimum weight vertex 
* separator out of it. It uses the node-based separator refinement for it.
**************************************************************************/
void ConstructSeparator(CtrlType *ctrl, GraphType *graph, float ubfactor)
{
  int i, j, k, nvtxs, nbnd;
  idxtype *xadj, *where, *bndind;

  nvtxs = graph->nvtxs;
  xadj = graph->xadj;
  nbnd = graph->nbnd;
  bndind = graph->bndind;

  where = idxcopy(nvtxs, graph->where, idxwspacemalloc(ctrl, nvtxs));

  /* Put the nodes in the boundary into the separator */
  for (i=0; i<nbnd; i++) {
    j = bndind[i];
    if (xadj[j+1]-xadj[j] > 0)  /* Ignore islands */
      where[j] = 2;
  }

  GKfree(&graph->rdata, LTERM);
  Allocate2WayNodePartitionMemory(ctrl, graph);
  idxcopy(nvtxs, where, graph->where);
  idxwspacefree(ctrl, nvtxs);

  ASSERT(IsSeparable(graph));

  Compute2WayNodePartitionParams(ctrl, graph);

  ASSERT(CheckNodePartitionParams(graph));

  FM_2WayNodeRefine(ctrl, graph, ubfactor, 8); 

  ASSERT(IsSeparable(graph));
}
示例#3
0
文件: srefine.c 项目: certik/libmesh
void Project2WayNodePartition(ctrl_t *ctrl, graph_t *graph)
{
  idx_t i, j, nvtxs;
  idx_t *cmap, *where, *cwhere;
  graph_t *cgraph;

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

  nvtxs = graph->nvtxs;
  cmap  = graph->cmap;

  Allocate2WayNodePartitionMemory(ctrl, graph);
  where = graph->where;
  
  /* Project the partition */
  for (i=0; i<nvtxs; i++) {
    where[i] = cwhere[cmap[i]];
    ASSERTP(where[i] >= 0 && where[i] <= 2, ("%"PRIDX" %"PRIDX" %"PRIDX" %"PRIDX"\n", 
          i, cmap[i], where[i], cwhere[cmap[i]]));
  }

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

  Compute2WayNodePartitionParams(ctrl, graph);
}
示例#4
0
文件: ometis.c 项目: iyer-arvind/gmsh
/*************************************************************************
* This function performs multilevel bisection. It performs multiple 
* bisections and selects the best.
**************************************************************************/
void MlevelNodeBisectionMultiple(CtrlType *ctrl, GraphType *graph, int *tpwgts, float ubfactor)
{
  int i, nvtxs, cnvtxs, mincut, tmp;
  GraphType *cgraph; 
  idxtype *bestwhere;

  if (ctrl->nseps == 1 || graph->nvtxs < (ctrl->oflags&OFLAG_COMPRESS ? 1000 : 2000)) {
    MlevelNodeBisection(ctrl, graph, tpwgts, ubfactor);
    return;
  }

  nvtxs = graph->nvtxs;

  if (ctrl->oflags&OFLAG_COMPRESS) { /* Multiple separators at the original graph */
    bestwhere = idxmalloc(nvtxs, "MlevelNodeBisection2: bestwhere");
    mincut = nvtxs;

    for (i=ctrl->nseps; i>0; i--) {
      MlevelNodeBisection(ctrl, graph, tpwgts, ubfactor);

      /* printf("%5d ", cgraph->mincut); */

      if (graph->mincut < mincut) {
        mincut = graph->mincut;
        idxcopy(nvtxs, graph->where, bestwhere);
      }

      GKfree(&graph->rdata, LTERM);
    
      if (mincut == 0)
        break;
    }
    /* printf("[%5d]\n", mincut); */

    Allocate2WayNodePartitionMemory(ctrl, graph);
    idxcopy(nvtxs, bestwhere, graph->where);
    free(bestwhere);

    Compute2WayNodePartitionParams(ctrl, graph);
  }
  else {  /* Coarsen it a bit */
    ctrl->CoarsenTo = nvtxs-1;

    cgraph = Coarsen2Way(ctrl, graph);

    cnvtxs = cgraph->nvtxs;

    bestwhere = idxmalloc(cnvtxs, "MlevelNodeBisection2: bestwhere");
    mincut = nvtxs;

    for (i=ctrl->nseps; i>0; i--) {
      ctrl->CType += 20; /* This is a hack. Look at coarsen.c */
      MlevelNodeBisection(ctrl, cgraph, tpwgts, ubfactor);

      /* printf("%5d ", cgraph->mincut); */

      if (cgraph->mincut < mincut) {
        mincut = cgraph->mincut;
        idxcopy(cnvtxs, cgraph->where, bestwhere);
      }

      GKfree(&cgraph->rdata, LTERM);
    
      if (mincut == 0)
        break;
    }
    /* printf("[%5d]\n", mincut); */

    Allocate2WayNodePartitionMemory(ctrl, cgraph);
    idxcopy(cnvtxs, bestwhere, cgraph->where);
    free(bestwhere);

    Compute2WayNodePartitionParams(ctrl, cgraph);

    Refine2WayNode(ctrl, graph, cgraph, ubfactor);
  }

}
示例#5
0
/*************************************************************************
* This function takes a bisection and constructs a minimum weight vertex 
* separator out of it. It uses an unweighted minimum-cover algorithm
* followed by node-based separator refinement.
**************************************************************************/
void ConstructMinCoverSeparator(CtrlType *ctrl, GraphType *graph, float ubfactor)
{
  int i, ii, j, jj, k, l, nvtxs, nbnd, bnvtxs[3], bnedges[2], csize;
  idxtype *xadj, *adjncy, *bxadj, *badjncy;
  idxtype *where, *bndind, *bndptr, *vmap, *ivmap, *cover;


  nvtxs = graph->nvtxs;
  xadj = graph->xadj;
  adjncy = graph->adjncy;

  nbnd = graph->nbnd;
  bndind = graph->bndind;
  bndptr = graph->bndptr;
  where = graph->where;

  vmap = idxwspacemalloc(ctrl, nvtxs);
  ivmap = idxwspacemalloc(ctrl, nbnd);
  cover = idxwspacemalloc(ctrl, nbnd);

  if (nbnd > 0) {
    /* Go through the boundary and determine the sizes of the bipartite graph */
    bnvtxs[0] = bnvtxs[1] = bnedges[0] = bnedges[1] = 0;
    for (i=0; i<nbnd; i++) {
      j = bndind[i];
      k = where[j];
      if (xadj[j+1]-xadj[j] > 0) {
        bnvtxs[k]++;
        bnedges[k] += xadj[j+1]-xadj[j];
      }
    }

    bnvtxs[2] = bnvtxs[0]+bnvtxs[1];
    bnvtxs[1] = bnvtxs[0];
    bnvtxs[0] = 0;

    bxadj = idxmalloc(bnvtxs[2]+1, "ConstructMinCoverSeparator: bxadj");
    badjncy = idxmalloc(bnedges[0]+bnedges[1]+1, "ConstructMinCoverSeparator: badjncy");

    /* Construct the ivmap and vmap */
    ASSERT(idxset(nvtxs, -1, vmap) == vmap);
    for (i=0; i<nbnd; i++) {
      j = bndind[i];
      k = where[j];
      if (xadj[j+1]-xadj[j] > 0) {
        vmap[j] = bnvtxs[k];
        ivmap[bnvtxs[k]++] = j;
      }
    }

    /* OK, go through and put the vertices of each part starting from 0 */
    bnvtxs[1] = bnvtxs[0];
    bnvtxs[0] = 0;
    bxadj[0] = l = 0;
    for (k=0; k<2; k++) {
      for (ii=0; ii<nbnd; ii++) {
        i = bndind[ii];
        if (where[i] == k && xadj[i] < xadj[i+1]) {
          for (j=xadj[i]; j<xadj[i+1]; j++) {
            jj = adjncy[j];
            if (where[jj] != k) {
              ASSERT(bndptr[jj] != -1); 
              ASSERTP(vmap[jj] != -1, ("%d %d %d\n", jj, vmap[jj], graph->bndptr[jj]));
              badjncy[l++] = vmap[jj];
            }
          }
          bxadj[++bnvtxs[k]] = l;
        }
      }
    }

    ASSERT(l <= bnedges[0]+bnedges[1]);

    MinCover(bxadj, badjncy, bnvtxs[0], bnvtxs[1], cover, &csize);

    IFSET(ctrl->dbglvl, DBG_SEPINFO,
      printf("Nvtxs: %6d, [%5d %5d], Cut: %6d, SS: [%6d %6d], Cover: %6d\n", nvtxs, graph->pwgts[0], graph->pwgts[1], graph->mincut, bnvtxs[0], bnvtxs[1]-bnvtxs[0], csize));

    for (i=0; i<csize; i++) {
      j = ivmap[cover[i]];
      where[j] = 2;
    }

    GKfree(&bxadj, &badjncy, LTERM);
  }
  else {
    IFSET(ctrl->dbglvl, DBG_SEPINFO,
      printf("Nvtxs: %6d, [%5d %5d], Cut: %6d, SS: [%6d %6d], Cover: %6d\n", nvtxs, graph->pwgts[0], graph->pwgts[1], graph->mincut, 0, 0, 0));
  }

  /* Prepare to refine the vertex separator */
  idxcopy(nvtxs, graph->where, vmap);
  GKfree(&graph->rdata, LTERM);

  Allocate2WayNodePartitionMemory(ctrl, graph);
  idxcopy(nvtxs, vmap, graph->where);
  idxwspacefree(ctrl, nvtxs+2*graph->nbnd);

  Compute2WayNodePartitionParams(ctrl, graph);

  ASSERT(CheckNodePartitionParams(graph));

  FM_2WayNodeRefine_OneSided(ctrl, graph, ubfactor, 6); 

  ASSERT(IsSeparable(graph));
}