function ker = rbf(arg)



if nargin == 0
   
   % this is the default constructor
   
   ker.gamma = 1;
   ker       = class(ker, 'rbf');
   
elseif isa(arg, 'rbf');
   
   % this is the copy constructor
   
   net = arg;
   
elseif nargin == 1
   
   if prod(size(arg)) ~= 1

      error('gamma must be a scalar');

   end

   ker.gamma = arg;
   ker       = class(ker, 'rbf');
  
else

   % there are no other constructors

   help rbf

end