subroutine minmax(n,vector,vmin,vmax)
c
c finds the minimum and maximum of the vector of length n, and
c stores the results in vmin and vmax (unless vmin or vmax
c already exceed this new minimum and maximum).
c
c Written by Greg Hammett 29-Jan-1991
c
 	implicit none	! force every variable's type to be declared.
	! (This is useful as a check for typographical errors.)
 
c declare arguments:
	integer n
	real vector(n)
	real vmin
	real vmax

c declare local variables:
	integer i

	if (n .ge. 1) then
	do 10 i=1,n
	vmin=min(vmin,vector(i))
 	vmax=max(vmax,vector(i))
10	continue
	endif
	return
	end