/*************************************************************************
* 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));
}
IsoString Filter::ToSource() const
{
IsoString s;
if ( IsValid() )
{
if ( IsSeparable() )
{
s += "SeparableFilter {\n";
s += " name { " + Separable().Name().ToUTF8() + " }\n";
s += " row-vector { ";
SeparableFilter::coefficient_vector H = Separable().RowFilter();
for ( int i = 0; i < H.Length(); ++i )
s.AppendFormat( ( H[i] < 0 ) ? "%.6f " : " %.6f ", H[i] );
s += "}\n";
s += " col-vector { ";
SeparableFilter::coefficient_vector V = Separable().ColFilter();
for ( int i = 0; i < V.Length(); ++i )
s.AppendFormat( ( V[i] < 0 ) ? "%.6f " : " %.6f ", V[i] );
s += "}\n";
}
else
{
s += "KernelFilter {\n";
s += " name { " + Kernel().Name().ToUTF8() + " }\n";
s += " coefficients {\n";
KernelFilter::coefficient_matrix M = Kernel().Coefficients();
for ( int i = 0; i < M.Rows(); ++i )
{
s += " ";
for ( int j = 0; ; )
{
s.AppendFormat( ( M[i][j] < 0 ) ? "%.6f " : " %.6f ", M[i][j] );
if ( ++j == M.Cols() )
break;
s += ' ';
}
s += '\n';
}
s += " }\n";
}
s += "}\n";
}
return s;
}
/*************************************************************************
* 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 ConstructMinCoverSeparator0(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);
for (i=0; i<nbnd; i++)
bndptr[bndind[i]] = -1;
for (nbnd=i=0; i<nvtxs; i++) {
if (where[i] == 2) {
bndind[nbnd] = i;
bndptr[i] = nbnd++;
}
}
}
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));
}
idxwspacefree(ctrl, nvtxs);
idxwspacefree(ctrl, graph->nbnd);
idxwspacefree(ctrl, graph->nbnd);
graph->nbnd = nbnd;
ASSERT(IsSeparable(graph));
}
