c----------------------------------------------------------------------
	function RNTGRL(n,r0,f)
c  simply integrates a function from 0 to infinity on n+1 uniformly
c  spaced points of y=1/(1+r/r0).
c 
c  author: Kieron Burke, 1.29.99
c      in: n - number of gridpoints
c          r0 - parameter for used grid
c          f - function values on gridpoints
c     out: return value of function: integral value of f between 0 and 
c          infinity
c   calls: sntgrl
	implicit real*8(a-h,o-z)
	parameter(m=1000000)
	dimension f(0:n)