#ifndef ROOT_TKDPDF
#define ROOT_TKDPDF

#ifndef ROOT_TKDInterpolatorBase
#include "TKDInterpolatorBase.h"
#endif

#ifndef ROOT_TKDTree
#include "TKDTree.h"
#endif

// Non parametric interpolation class based on local polinomial regression.
// The class can be used to approximate PDF together with TKDTree or for
// general regression when the data points are given.

template <typename Index, typename Value> class TKDTree;
typedef class TKDTree<Int_t, Float_t> TKDTreeIF;
class TTree;
class TLinearFitter;
class TKDPDF : public TKDTreeIF, public TKDInterpolatorBase
{
public:
  TKDPDF();
  TKDPDF(TTree *t, const Char_t *var, const Char_t *cut = 0, UInt_t bsize = 100, Long64_t nentries = 1000000000, Long64_t firstentry = 0);
  TKDPDF(Int_t npoints, Int_t ndim, UInt_t bsize, Float_t **data);
  ~TKDPDF();

  inline Bool_t GetDataPoint(Int_t n, Float_t *p) const;
  inline Int_t  GetNodeIndex(const Float_t *p);
  void          DrawNode(Int_t tnode, UInt_t ax1=0, UInt_t ax2=1);

private:
  TKDPDF(const TKDPDF &);
  TKDPDF& operator=(const TKDPDF &);
  Bool_t    Build(Int_t ndim = 0);

          
  ClassDef(TKDPDF, 1)   // data interpolator based on KD tree
};


//__________________________________________________________________
Bool_t	TKDPDF::GetDataPoint(Int_t n, Float_t *p) const
{
  if(n < 0 || n >= fNPoints) return kFALSE;
  if(!fData) return kFALSE;
    
  for(int i=0; i<fNDim; i++) p[i] = fData[i][n];
  return kTRUE;
}

//__________________________________________________________________
Int_t	TKDPDF::GetNodeIndex(const Float_t *p)
{
  return FindNode(p) - fNNodes;
}

#endif