fastmks_stat.hpp

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#ifndef MLPACK_METHODS_FASTMKS_FASTMKS_STAT_HPP
#define MLPACK_METHODS_FASTMKS_FASTMKS_STAT_HPP
 
#include <mlpack/prereqs.hpp>
#include <mlpack/core/tree/tree_traits.hpp>
 
namespace mlpack {
namespace fastmks {
 
class FastMKSStat
{
 public:
  FastMKSStat() :
      bound(-DBL_MAX),
      selfKernel(0.0),
      lastKernel(0.0),
      lastKernelNode(NULL)
  { }
 
  template<typename TreeType>
  FastMKSStat(const TreeType& node) :
      bound(-DBL_MAX),
      lastKernel(0.0),
      lastKernelNode(NULL)
  {
    // Do we have to calculate the centroid?
    if (tree::TreeTraits<TreeType>::FirstPointIsCentroid)
    {
      // If this type of tree has self-children, then maybe the evaluation is
      // already done.  These statistics are built bottom-up, so the child stat
      // should already be done.
      if ((tree::TreeTraits<TreeType>::HasSelfChildren) &&
          (node.NumChildren() > 0) &&
          (node.Point(0) == node.Child(0).Point(0)))
      {
        selfKernel = node.Child(0).Stat().SelfKernel();
      }
      else
      {
        selfKernel = sqrt(node.Metric().Kernel().Evaluate(
            node.Dataset().col(node.Point(0)),
            node.Dataset().col(node.Point(0))));
      }
    }
    else
    {
      // Calculate the centroid.
      arma::vec center;
      node.Center(center);
 
      selfKernel = sqrt(node.Metric().Kernel().Evaluate(center, center));
    }
  }
 
  double SelfKernel() const { return selfKernel; }
  double& SelfKernel() { return selfKernel; }
 
  double Bound() const { return bound; }
  double& Bound() { return bound; }
 
  double LastKernel() const { return lastKernel; }
  double& LastKernel() { return lastKernel; }
 
  void* LastKernelNode() const { return lastKernelNode; }
  void*& LastKernelNode() { return lastKernelNode; }
 
  template<typename Archive>
  void serialize(Archive& ar, const unsigned int /* version */)
  {
    ar & BOOST_SERIALIZATION_NVP(bound);
    ar & BOOST_SERIALIZATION_NVP(selfKernel);
 
    // Void out last kernel information on load.
    if (Archive::is_loading::value)
    {
      lastKernel = 0.0;
      lastKernelNode = NULL;
    }
  }
 
 private:
  double bound;
 
  double selfKernel;
 
  double lastKernel;
 
  void* lastKernelNode;
};
 
} // namespace fastmks
} // namespace mlpack
 
#endif