new version of the kdTree from Anna

In particular, FindNearestNeighbors() function has been completely rewritten, and now 1) actually works correctly, 2) uses Euclidean metric, 3) has more user friendly calling sequence, 4) is recursive and more readable (as fast as before). Some new functions had to be added to TKDTree for this, such as Distance(), which finds distance between a random point and a point in  the kdtree, and DistanceToNode() which finds the distance between a point and a node of the kdtree, GetNodePointsIndexes() which returns ranges of indexes of original points, contained in a given node. Also, the test macro has been updated with a test function, that compares TKDTree::FindNearestNeighbors() results with simple sorting.

fixed also some problem in the TMath test


git-svn-id: http://root.cern.ch/svn/root/trunk@26356 27541ba8-7e3a-0410-8455-c3a389f83636

Author: lmoneta

math/mathcore/inc/TKDTree.h

@@ -19,16 +19,21 @@ template <typename Index, typename Value> class TKDTree : public TObject
 
    void            Build();  // build the tree
 
+   Double_t        Distance(const Value *point, Index ind, Int_t type=2) const;
+   void            DistanceToNode(const Value *point, Index inode, Value &min, Value &max, Int_t type=2);
+
    // Get indexes of left and right daughter nodes
-   Int_t GetLeft(Int_t inode)  const    {return inode*2+1;}
-   Int_t GetRight(Int_t inode) const    {return (inode+1)*2;}
-   Int_t GetParent(Int_t inode) const  {return inode/2;}
+   Int_t   GetLeft(Int_t inode)  const    {return inode*2+1;}
+   Int_t   GetRight(Int_t inode) const    {return (inode+1)*2;}
+   Int_t   GetParent(Int_t inode) const  {return (inode-1)/2;}
    //  
    // Other getters
    Index*  GetPointsIndexes(Int_t node) const;
+   void    GetNodePointsIndexes(Int_t node, Int_t &first1, Int_t &last1, Int_t &first2, Int_t &last2) const;
    UChar_t GetNodeAxis(Int_t id) const {return (id < 0 || id >= fNNodes) ? 0 : fAxis[id];}
    Value   GetNodeValue(Int_t id) const {return (id < 0 || id >= fNNodes) ? 0 : fValue[id];}
    Int_t   GetNNodes() const {return fNNodes;}
+   Int_t   GetTotalNodes() const {return fTotalNodes;}
    Value*  GetBoundaries();
    Value*  GetBoundariesExact();
    Value*  GetBoundary(const Int_t node);
@@ -44,15 +49,17 @@ template <typename Index, typename Value> class TKDTree : public TObject
    Index*  GetIndPoints() {return fIndPoints;}
    Index   GetBucketSize() {return fBucketSize;}
 
-   Bool_t  FindNearestNeighbors(const Value *point, const Int_t kNN, Index *&i, Value *&d);
-   Index   FindNode(const Value * point);
+   void    FindNearestNeighbors(const Value *point, const Int_t k, Index *ind, Value *dist);
+   Index   FindNode(const Value * point) const;
    void    FindPoint(Value * point, Index &index, Int_t &iter);
    void    FindInRangeA(Value * point, Value * delta, Index *res , Index &npoints,Index & iter, Int_t bnode);
    void    FindInRangeB(Value * point, Value * delta, Index *res , Index &npoints,Index & iter, Int_t bnode);
    void    FindBNodeA(Value * point, Value * delta, Int_t &inode);
    Bool_t  IsTerminal(Index inode) const {return (inode>=fNNodes);}
    Int_t   IsOwner() { return fDataOwner; }
    Value   KOrdStat(Index ntotal, Value *a, Index k, Index *index) const;
+
+
    void    MakeBoundaries(Value *range = 0x0);
    void    MakeBoundariesExact();
    void    SetData(Index npoints, Index ndim, UInt_t bsize, Value **data);
@@ -64,11 +71,12 @@ template <typename Index, typename Value> class TKDTree : public TObject
    TKDTree(const TKDTree &); // not implemented
    TKDTree<Index, Value>& operator=(const TKDTree<Index, Value>&); // not implemented
    void CookBoundaries(const Int_t node, Bool_t left);
-   
+   void UpdateNearestNeighbors(Index inode, const Value *point, Int_t kNN, Index *ind, Value *dist);
 
  protected:
    Int_t   fDataOwner;  //! 0 - not owner, 2 - owner of the pointer array, 1 - owner of the whole 2-d array
    Int_t   fNNodes;     // size of node array
+   Int_t   fTotalNodes; // total number of nodes (fNNodes + terminal nodes)
    Index   fNDim;       // number of dimensions
    Index   fNDimm;      // dummy 2*fNDim
    Index   fNPoints;    // number of multidimensional points
@@ -88,12 +96,6 @@ template <typename Index, typename Value> class TKDTree : public TObject
                         //  fOffset returns the index in the fIndPoints array of the first point
                         //  that belongs to the first node on the second row.
 
-   // kNN related data
-   Int_t   fkNNdim;     //! current kNN arrays allocated dimension
-   Index   *fkNN;       //! k nearest neighbors indexes
-   Value   *fkNNdist;   //! k nearest neighbors distances
-   Value   *fDistBuffer;//! working space for kNN
-   Index   *fIndBuffer; //! working space for kNN
 
    ClassDef(TKDTree, 1)  // KD tree
 };