C+
C NAME:
C	CosdLookup
C PURPOSE:
C	Calculates cos(x) using lookup table
C CATEGORY:
C	Math
C CALLING SEQUENCE:
	function CosdLookup(X)
C INPUTS:
C	X		real		X-coordinate
C OUTPUTS:
C	F		real		cos(x) from table lookup
C CALLS:
C	FLINT, cosd
C SEE ALSO:
C	SinLookup, GaussLookup
C MODIFICATION HISTORY:
C	SEP-2003, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
C-
	    real	X

	parameter	(N =9000)
	parameter	(dA=90.0/N)

	real		F(0:N)

	logical		bInit	/.TRUE./
	save		bInit, F

	if (bInit) then		! Set up lookup table

	    do I=0,N
		F(I) = cosd(dA*I)
	    end do

	    bInit = .FALSE.

	end if

	A = mod(mod(X,360.0)+360.0,360.0)	! Scale to [0,360]

	I = 1
	if (A .gt. 180.0) A = 360.0-A		! cos(-x) = cos(x)

	if (A .gt.  90.0) then			! cos(180-x) = -cos(x)
	    A = 180.0-A
	    I = -1
	end if

	! A now is in [0,90]

	CosdLookup = I*FLINT(1,N+1,F,1.0+A/dA,0.0)

	return
	end