c----------------------------------------------------------------------
	function SNTGRL(n,f)
c simply integrates a function from 0 to 1 on n+1 uniformly
c spaced points; n must be  at least 8.
c
c author: Adapted from Numerical Recipes, 4.1.14, Kieron Burke, 1.29.99
c     in: n  - number of gridpoints
c         f  - function values corresponding to equally spaced gridpoints
c    out: return value of function: integral value of f between 0 and 1
c  calls: --
	implicit real*8(a-h,o-z)
	dimension f(0:n)