/* Random partitioning. Sequence partitioning with vertices in random order. */
static int coarse_part_random (
ZZ *zz,
HGraph *hg,
int p,
float *part_sizes,
Partition part,
PHGPartParams *hgp
)
{
int i, err=0, *order=NULL;
char *yo = "coarse_part_random";
if (!(order = (int*) ZOLTAN_MALLOC (hg->nVtx*sizeof(int)))) {
ZOLTAN_FREE (&order);
ZOLTAN_PRINT_ERROR (zz->Proc, yo, "Insufficient memory.");
return ZOLTAN_MEMERR;
}
for (i=0; i<hg->nVtx; i++) {
order[i] = i;
}
/* Randomly permute order array */
Zoltan_Rand_Perm_Int (order, hg->nVtx, NULL);
/* Call sequence partitioning with random order array. */
err = seq_part (zz, hg, order, p, part_sizes, part, hgp);
ZOLTAN_FREE (&order);
return err;
}
int Zoltan_PHG_Vertex_Visit_Order(
ZZ *zz,
HGraph *hg,
PHGPartParams *hgp,
int *order)
{
int i, j, edge;
int *ldegree=NULL, *gdegree=NULL; /* local/global degree */
int *lpins=NULL, *gpins=NULL; /* local/global sum of pins */
char *yo= "Zoltan_PHG_Vertex_Visit_Order";
/* Start with linear order. */
for (i=0; i<hg->nVtx; i++)
order[i] = i;
/* Permute order array according to chosen strategy. */
switch (hgp->visit_order){
case 0:
/* random node visit order (recommended) */
/* Synchronize so each proc in column visits in same order */
Zoltan_Srand_Sync(Zoltan_Rand(NULL), &(hg->comm->RNGState_col),
hg->comm->col_comm);
Zoltan_Rand_Perm_Int (order, hg->nVtx, &(hg->comm->RNGState_col));
break;
case 1:
/* linear (natural) vertex visit order */
break;
case 2:
{
/* increasing vertex weight */
float *tmpvwgt;
if (hg->VtxWeightDim == 1)
tmpvwgt = hg->vwgt;
else {
/* Sort based on first component of multidimensional weight */
tmpvwgt = (float *) ZOLTAN_MALLOC(hg->nVtx * sizeof(float));
for (i = 0; i < hg->nVtx; i++)
tmpvwgt[i] = hg->vwgt[i*hg->VtxWeightDim];
}
Zoltan_quicksort_pointer_inc_float (order, tmpvwgt, 0, hg->nVtx-1);
if (tmpvwgt != hg->vwgt) ZOLTAN_FREE(&tmpvwgt);
break;
}
case 3:
/* increasing vertex degree */
/* intentionally fall through into next case */
case 4:
/* increasing vertex degree, weighted by # pins */
/* allocate 4 arrays of size hg->nVtx with a single malloc */
if (!(ldegree = (int *) ZOLTAN_MALLOC (4*sizeof(int) * hg->nVtx))){
ZOLTAN_PRINT_WARN(zz->Proc, yo, "Out of memory");
ZOLTAN_FREE (&ldegree);
return ZOLTAN_MEMERR;
}
/* first local data, then global data */
lpins = ldegree + hg->nVtx;
gdegree = lpins + hg->nVtx;
gpins = gdegree + hg->nVtx;
/* loop over vertices */
for (i=0; i<hg->nVtx; i++){
ldegree[i] = hg->vindex[i+1] - hg->vindex[i]; /* local degree */
lpins[i] = 0;
/* loop over edges, sum up #pins */
for (j= hg->vindex[i]; j < hg->vindex[i+1]; j++) {
edge = hg->vedge[j];
lpins[i] += hg->hindex[edge+1] - hg->hindex[edge];
}
}
/* sum up local degrees in each column to get global degrees */
/* also sum up #pins in same communication */
MPI_Allreduce(ldegree, gdegree, 2*hg->nVtx, MPI_INT, MPI_SUM,
hg->comm->col_comm);
/* sort by global values. same on every processor. */
if (hgp->visit_order == 3)
Zoltan_quicksort_pointer_inc_int_int (order, gdegree, gpins,
0, hg->nVtx-1);
else /* hgp->visit_order == 4 */
Zoltan_quicksort_pointer_inc_int_int (order, gpins, gdegree,
0, hg->nVtx-1);
ZOLTAN_FREE (&ldegree);
break;
/* add more cases here */
}
return ZOLTAN_OK;
}
