class TMVA::PDEFoamKernelGauss: public TMVA::PDEFoamKernelBase

 Default constructor for streamer

 Copy constructor

 Gaussian kernel estimator.  It returns the cell value 'cv',
 corresponding to the event vector 'txvec' (in foam coordinates)
 weighted by the cell values of all other cells, where the weight
 is a gaussian function.

 Parameters:

 - foam - the pdefoam to search in

 - txvec - event vector in foam coordinates [0,1]

 - cv - cell value to estimate

 This function returns the average value 'cv' of only nearest
 neighbor cells.  It is used in cases when a cell value is
 undefined and the cell value shall be estimated by the
 (well-defined) cell values of the neighbor cells.

 Parameters:
 - foam - the foam to search in
 - txvec - event vector, transformed into foam coordinates [0, 1]
 - cv - cell value, see definition of ECellValue

 Returns the gauss weight between the 'cell' and a given coordinate 'txvec'.

 Parameters:
 - cell - the cell

 - txvec - the transformed event variables (in [0,1]) (coordinates <0 are
   set to 0, >1 are set to 1)

 Returns:
 exp(-(d/sigma)^2/2), where
  - d - is the euclidean distance between 'txvec' and the point of the 'cell'
    which is most close to 'txvec' (in order to avoid artefacts because of the
    form of the cells).
  - sigma = 1/VolFrac