/**
 *  \file point_clustering.cpp
 *  \brief Cluster sets of points.
 *
 *  Copyright 2007-2013 IMP Inventors. All rights reserved.
 *
 */
#include <IMP/statistics/utility.h>
#include <IMP/algebra/vector_search.h>
#include <IMP/base/object_macros.h>
IMPSTATISTICS_BEGIN_NAMESPACE


algebra::VectorKDs get_centroids(Embedding* d, PartitionalClustering *pc) {
  Pointer<Embedding> pd(d);
  Pointer<PartitionalClustering> ppc(pc);
  algebra::VectorKDs ret(pc->get_number_of_clusters());
  for (unsigned int i=0; i< ret.size(); ++i) {
    algebra::VectorKD cur
      = algebra::get_zero_vector_kd(d->get_point(0).get_dimension());
    Ints cc= pc->get_cluster(i);
    for (unsigned int j=0; j< cc.size(); ++j) {
      cur+= d->get_point(cc[j]);
    }
    cur/= cc.size();
    ret[i]=cur;
  }
  return ret;
}

Ints get_representatives(Embedding* d, PartitionalClustering *pc) {
  Pointer<Embedding> pd(d);
  Pointer<PartitionalClustering> ppc(pc);
  algebra::VectorKDs centroids= get_centroids(d, pc);
  Ints ret(centroids.size());
  IMP_NEW(algebra::NearestNeighborKD, nn, (d->get_points()));
  for (unsigned int i=0; i < centroids.size(); ++i) {
    ret[i]= nn->get_nearest_neighbors(centroids[i], 1)[0];
  }
  return ret;
}



IMPSTATISTICS_END_NAMESPACE