void kdtree_sampling
(Master& master, //!< master object
const Assigner& assigner, //!< assigner object
int dim, //!< dimensionality
const ContinuousBounds& domain, //!< global data extents
std::vector<Point> Block::* points, //!< input points to sort into kd-tree
size_t samples, //!< number of samples to take in each block
bool wrap = false)//!< periodic boundaries in all dimensions
{
if (assigner.nblocks() & (assigner.nblocks() - 1))
{
fprintf(stderr, "KD-tree requires a number of blocks that's a power of 2, got %d\n", assigner.nblocks());
std::abort();
}
typedef diy::RegularContinuousLink RCLink;
for (size_t i = 0; i < master.size(); ++i)
{
RCLink* link = static_cast<RCLink*>(master.link(i));
*link = RCLink(dim, domain, domain);
if (wrap) // set up the links to self
{
diy::BlockID self = { master.gid(i), master.communicator().rank() };
for (int j = 0; j < dim; ++j)
{
diy::Direction dir, wrap_dir;
// left
dir.x[j] = -1; wrap_dir.x[j] = -1;
link->add_neighbor(self);
link->add_bounds(domain);
link->add_direction(dir);
link->add_wrap(wrap_dir);
// right
dir.x[j] = 1; wrap_dir.x[j] = 1;
link->add_neighbor(self);
link->add_bounds(domain);
link->add_direction(dir);
link->add_wrap(wrap_dir);
}
}
}
detail::KDTreeSamplingPartition<Block,Point> kdtree_partition(dim, points, samples);
detail::KDTreePartners partners(dim, assigner.nblocks(), wrap, domain);
reduce(master, assigner, partners, kdtree_partition);
// update master.expected to match the links
int expected = 0;
for (size_t i = 0; i < master.size(); ++i)
expected += master.link(i)->size_unique();
master.set_expected(expected);
}
