TDataPoint.icc

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// @(#)root/mathcore:$Id: IFunction.h 24537 2008-06-25 11:01:23Z moneta $
// Authors: C. Gumpert    09/2011
/**********************************************************************
 *                                                                    *
 * Copyright (c) 2011 , LCG ROOT MathLib Team                         *
 *                                                                    *
 *                                                                    *
 **********************************************************************/
//
// Implementation of template functions for TDataPoint class
//


#ifndef ROOT_TDataPoint_ICC
#define ROOT_TDataPoint_ICC

#include <cassert>
#include <math.h>

namespace ROOT
{
namespace Math
{


//______________________________________________________________________________
// Begin_Html
// <center><h2>TDataPoint - class representing a data point</h2></center>
//
// This class can be used for describing data points in a high-dimensional space.
// The (positive) dimension is specified by the first template parameter. The second
// template paramter can be used to tweak the precision of the stored coordinates. By
// default all coordinates are stored with 4 byte float precision. In addition to the
// coordinates a weight can be assigned to each data point allowing the representation
// of fields in high dimensions.
// Basic functionality for accessing/modifying the coordinates/weight are provided
// as well as a comparison method and the basic euclidian metric.
// End_Html

//______________________________________________________________________________
template<unsigned int K,typename _val_type>
TDataPoint<K,_val_type>::TDataPoint():
   m_fWeight(1)
{
   //standard constructor
   //
   //sets the weight to 1 and initialises all coordinates with 0

   // at least one dimension
   assert(kDimension > 0);

   for(UInt_t k = 0; k < K; ++k)
      m_vCoordinates[k] = 0;
}

#ifndef __MAKECINT__
//______________________________________________________________________________
template<unsigned int K,typename _val_type>
template<typename _coord_type>
TDataPoint<K,_val_type>::TDataPoint(const _coord_type* pData,_val_type fWeight):
  m_fWeight(fWeight)
{
   //constructor initialising the data point from an array
   //
   //Input: pData   - arrray with kDimension coordinates
   //       fWeight - weight (default = 1)

   // at least one dimension
   assert(kDimension > 0);
   // fill coordinates
   for(unsigned int i = 0; i < kDimension; ++i)
      m_vCoordinates[i] = pData[i];
}

//______________________________________________________________________________
template<unsigned int K,typename _val_type>
template<typename _val>
_val_type TDataPoint<K,_val_type>::Distance(const TDataPoint<K,_val>& rPoint) const
{
   //euclidian distance
   //
   //returns the euclidian distance to the given data point
   //
   //Input: rPoint - data point of same dimensionality

   _val_type fDist2 = 0;
   for(unsigned int i = 0; i < kDimension; ++i)
      fDist2 += pow(GetCoordinate(i) - rPoint.GetCoordinate(i),2);

   return sqrt(fDist2);
}
#endif

//______________________________________________________________________________
template<unsigned int K,typename _val_type>
inline _val_type TDataPoint<K,_val_type>::GetCoordinate(unsigned int iAxis) const
{
   //returns the coordinate at the given axis
   //
   //Input: iAxis - axis in the range of [0...kDimension-1]

   assert(iAxis < kDimension);
   return m_vCoordinates[iAxis];
}

//______________________________________________________________________________
template<unsigned int K,typename _val_type>
inline void TDataPoint<K,_val_type>::SetCoordinate(unsigned int iAxis,_val_type fValue)
{
   //sets the coordinate along one axis
   //
   //Input: iAxis  - axis in the range of [0...kDimension-1]
   //       fValue - new coordinate

   assert(iAxis < kDimension);
   m_vCoordinates[iAxis] = fValue;
}

//______________________________________________________________________________
template<unsigned int K,typename _val_type>
inline Bool_t TDataPoint<K,_val_type>::Less(TDataPoint<K,_val_type>& rPoint,unsigned int iAxis) const
{
   //compares two points at a given axis
   //
   // returns: this_point.at(iAxis) < rPoint.at(iAxis)
   //
   //Input: rPoint - second point to compare to (of same dimensionality)
   //       iAxis  - axis in the range of [0...kDimension-1]

   assert(iAxis < kDimension);
   return (m_vCoordinates[iAxis] < rPoint.GetCoordinate(iAxis));
}

}//namespace Math
}//namespace ROOT


#endif //ROOT_TDataPoint_ICC