/*----------------------------------------------------------------------------
* R T L - F l a s h F i l e S y s t e m
*-------------------------------------------------------------------
function r = r(kernel)
% R
%
% This method returns an upper bound on
%
% R > k(x1, x1) - k(x1, x2)
%
% for arbitrary x1 and x2. For a Gaussian radial basis kernel R = 1.
%
% File