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mlpack/fastlib/u/nvasil/tree/knn_node_impl.h
T
2007-06-08 02:50:07 +00:00

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C++

#ifndef KNN_NODE_IMPL_H_
#define KNN_NODE_IMPL_H_
#define TEMPLATE__ \
template<typename TYPELIST, bool diagnostic>
#define KNN_NODE__ \
KnnNode<TYPELIST, diagnostic>
TEMPLATE__
KNN_NODE__::KnnNode() {
left_.SetNULL();
right_.SetNULL();
points_.SetNULL();
node_id_ = numeric_limits<index_t>::max();
min_dist_so_far_=numeric_limits<Precision_t>::max();
}
TEMPLATE__
void KNN_NODE__::Init(const BoundingBox_t &box,
const NodeCachedStatistics_t &statistics,
index_t node_id,
index_t num_of_points) {
box_.Alias(box);
statistics_.Alias(statistics);
node_id_ = node_id;
num_of_points_ = num_of_points;
}
TEMPLATE__
void KNN_NODE__::Init(const typename KNN_NODE__::BoundingBox_t &box,
const typename KNN_NODE__::NodeCachedStatistics_t &statistics,
index_t node_id,
index_t start,
index_t num_of_points,
int32 dimension,
BinaryDataset<Precision_t> *dataset) {
box_.Alias(box);
statistics_.Alias(statistics);
node_id_ = node_id;
num_of_points_ = num_of_points;
points_.Reset(Allocator_t::template malloc<Precision_t>
(num_of_points_*dimension));
index_.Reset(Allocator_t::template malloc<index_t>(num_of_points_));
points_.Lock();
index_.Lock();
for(index_t i=start; i<start+num_of_points_; i++) {
for(int32 j=0; j<dimension; j++) {
points_[(i-start)*dimension+j]=dataset->At(i,j);
}
index_[i-start]=dataset->get_id(i);
}
points_.Unlock();
index_.Unlock();
}
TEMPLATE__
KNN_NODE__::~KnnNode() {
}
TEMPLATE__
void *KNN_NODE__::operator new(size_t size) {
typename Allocator_t::template Ptr<Node_t> temp;
temp.Reset(Allocator_t::malloc(size));
return (void *)temp.get();
}
TEMPLATE__
void KNN_NODE__::operator delete(void *p) {
}
TEMPLATE__
template<typename POINTTYPE>
pair<typename KNN_NODE__::NodePtr_t, typename KNN_NODE__::NodePtr_t>
KNN_NODE__::ClosestChild(POINTTYPE point, int32 dimension,
ComputationsCounter<diagnostic> &comp) {
left_.Lock();
right_.Lock();
return box_.ClosestChild(left_, right_, point, dimension, comp);
left_.Unlock();
right_.Unlock();
}
TEMPLATE__
inline
pair<pair<typename KNN_NODE__::NodePtr_t, typename KNN_NODE__::Precision_t>,
pair<typename KNN_NODE__::NodePtr_t, typename KNN_NODE__::Precision_t> >
KNN_NODE__::ClosestNode(typename KNN_NODE__::NodePtr_t ptr1,
typename KNN_NODE__::NodePtr_t ptr2,
int32 dimension,
ComputationsCounter<diagnostic> &comp) {
ptr1.Lock();
ptr2.Lock();
Precision_t dist1 = BoundingBox_t::Distance(box_, ptr1->get_box(),
dimension, comp);
Precision_t dist2 = BoundingBox_t::Distance(box_, ptr2->get_box(),
dimension, comp);
ptr1.Unlock();
ptr2.Unlock();
if (dist1<dist2) {
return make_pair(make_pair(ptr1, dist1), make_pair(ptr2, dist2));
} else {
return make_pair(make_pair(ptr2,dist2), make_pair(ptr1, dist1));
}
}
TEMPLATE__
template<typename POINTTYPE>
inline void KNN_NODE__::FindNearest(POINTTYPE query_point,
vector<pair<typename KNN_NODE__::Precision_t,
typename KNN_NODE__::Point_t> > &nearest,
index_t knns,
int32 dimension,
typename KNN_NODE__::PointIdDiscriminator_t &discriminator,
ComputationsCounter<diagnostic> &comp) {
for(index_t i=0; i<num_of_points_; i++) {
comp.UpdateDistances();
// we have to check if we are comparing the point with itself
if (unlikely(discriminator.AreTheSame(index_[i],
query_point.get_id())==true)) {
continue;
}
Precision_t dist = BoundingBox_t::
template Distance(query_point,
points_.get_p()+i*dimension,
dimension);
// for k nearest neighbors
Point_t point;
point.Alias(points_.get()+i*dimension, index_[i]);
nearest.push_back(make_pair(dist, point));
}
// for k-nearest neighbors
typename std::vector<pair<Precision_t, Point_t> >::iterator it;
it=nearest.begin()+knns;
std::sort(nearest.begin(),
nearest.end(),
PairComparator());
if (likely(nearest.size()>(uint32)knns)) {
nearest.erase(it, nearest.end());
} else {
pair<Precision_t, Point_t> dummy;
dummy.first=numeric_limits<Precision_t>::max();
index_t extra_size=(index_t)(knns-nearest.size());
for(index_t i=0; i<extra_size; i++) {
nearest.push_back(dummy);
}
}
}
TEMPLATE__
inline void KNN_NODE__::FindAllNearest(
NodePtr_t query_node,
typename KNN_NODE__::Precision_t &max_neighbor_distance,
index_t knns,
int32 dimension,
typename KNN_NODE__::PointIdDiscriminator_t &discriminator,
ComputationsCounter<diagnostic> &comp) {
points_.Lock();
index_.Lock();
query_node->points_.Lock();
query_node->index_.Lock();
query_node->kneighbors_.Lock();
query_node->distances_.Lock();
Precision_t max_local_distance = 0;
for(index_t i=0; i<query_node->num_of_points_; i++) {
Precision_t distance;
// for k nearest neighbors
// get the current maximum distance for the specific point
distance = query_node->distances_[i*knns+knns-1];
// We should check whether this speeds up or slows down
// the performance
comp.UpdateComparisons();
Precision_t *temp_point=query_node->points_.get_p()+i*dimension;
if (this->box_.CrossesBoundaries(temp_point,
dimension,
distance,
comp)) {
// for k nearest neighbors
vector<pair<Precision_t, Point_t> > temp(knns);
for(int32 j=0; j<knns; j++) {
temp[j].first=query_node->distances_[i*knns+j];
temp[j].second=query_node->kneighbors_[i*knns+j];
}
NullPoint_t point;
point.Alias(query_node->points_.get_p()+i*dimension,
query_node->index_[i]);
FindNearest(point, temp,
knns, dimension,
discriminator, comp);
DEBUG_ASSERT_MSG((index_t)temp.size()==knns,
"During %i-nn seach, returned %u results",(int)knns,
(unsigned int)temp.size());
for(int32 j=0; j<knns; j++) {
query_node->kneighbors_[i*knns+j]=temp[j].second;
query_node->distances_[i*knns+j]=temp[j].first;
}
// Estimate the maximum nearest neighbor distance
comp.UpdateComparisons();
if (max_local_distance < temp.back().first) {
max_local_distance = temp.back().first;
}
}
if (max_local_distance < distance) {
max_local_distance = distance;
}
}
if (max_neighbor_distance>max_local_distance) {
max_neighbor_distance=max_local_distance;
}
points_.Unlock();
index_.Unlock();
query_node->points_.Unlock();
query_node->index_.Unlock();
query_node->kneighbors_.Unlock();
query_node->distances_.Unlock();
}
TEMPLATE__
void KNN_NODE__::OutputNeighbors(NNResult *out, index_t knns) {
kneighbors_.Lock();
distances_.Lock();
index_.Lock();
for(index_t i=0; i<num_of_points_; i++) {
for(index_t j=0; j<knns; j++) {
out[i*knns+j].point_id_ =index_[i];
out[i*knns+j].nearest_ = kneighbors_[i*knns+j];
out[i*knns+j].distance_ = distances_[i*knns+j];
}
}
index_.Unlock();
kneighbors_.Unlock();
distances_.Unlock();
}
TEMPLATE__
void KNN_NODE__::OutputNeighbors(FILE *fp, index_t knns) {
kneighbors_.Lock();
distances_.Lock();
index_.Lock();
NNResult result;
for(index_t i=0; i<num_of_points_; i++) {
for(index_t j=0; j<knns; j++) {
result.point_id_ = index_[i];
result.nearest_ = kneighbors_[i*knns+j];
result.distance_ = distances_[i*knns+j];
fwrite(&result, sizeof(NNResult),1 , fp);
}
}
index_.Unlock();
kneighbors_.Unlock();
distances_.Unlock();
}
TEMPLATE__
void KNN_NODE__::OutputNeighborsText(FILE *fp, index_t knns) {
kneighbors_.Lock();
distances_.Lock();
index_.Lock();
NNResult result;
for(index_t i=0; i<num_of_points_; i++) {
for(index_t j=0; j<knns; j++) {
fprintf(fp, "%lli %lli %lg\n",
(signed long long)index_[i],
(signed long long)kneighbors_[i*knns+j].get_id(),
(double) distances_[i*knns+j]);
}
}
index_.Unlock();
kneighbors_.Unlock();
distances_.Unlock();
}
TEMPLATE__
string KNN_NODE__::Print(int32 dimension) {
points_.Lock();
index_.Lock();
char buf[8192];
string str;
if (!IsLeaf()) {
sprintf(buf, "Node: %llu\n", (unsigned long long)node_id_);
str.append(buf);
} else {
sprintf(buf, "Leaf: %llu\n", (unsigned long long)node_id_);
str.append(buf);
}
str.append(box_.Print(dimension));
str.append("num_of_points: ");
sprintf(buf,"%llu\n", (unsigned long long)num_of_points_);
str.append(buf);
if (IsLeaf()) {
for(index_t i=0; i<num_of_points_; i++) {
for(int32 j=0; j<dimension; j++) {
sprintf(buf,"%lg ", points_[i*dimension+j]);
str.append(buf);
}
sprintf(buf, "-%llu \n",(unsigned long long) index_[i]);
str.append(buf);
}
}
points_.Unlock();
index_.Unlock();
return str;
}
#undef TEMPLATE__
#undef KNN_NODE__
#endif /*KNN_NODE_IMPL_H_*/