C+
C NAME:
C	Get3Dval
C PURPOSE:
C	3D linear interpolationInterpolates values from positions specified as
C	XC,XL,RP (modified Carrington variable, latitude (deg) and distance (AU)
C CATEGORY:
C	Data processing
C CALLING SEQUENCE:
	subroutine Get3Dval(XCbeg,Xcend,RR,dRR,nLng,nLat,nRad,F3D,N,XC,XL,RP,FF)
C INPUTS: (all input is read-only)
C	RR		real
C	dRR		real		Distance between individual maps (in AU)
C	nLng		integer		# longitudes
C	nLat 		integer		# latitudes
C	nRad		integer		# DF maps formed (height begins ~0 AU)
C	F3D(nLng,nLat,nRad) real	3D array (longitude, latitude, radial distance)
C	N		integer		# points
C					
C	XC(N)		real		Modified Carrington variable
C	XL(N)		real		Heliographic latitude (deg)
C	RP(N)		real		Heliocentric distance (AU)
C OUTPUTS:
C	FF(N)		real		Interpolated function values
C CALLS:
C	FLINT
C INCLUDE:
C	include		'mapcoordinates.h'
C PROCEDURE:
C >	The modified Carrington variable is mapped to the range [1,nLng]
C	The latitude is mapped to the range [1,nLat]
C	The distance is mapped to the range [1,nRad]
C >	For each point, if any of the neighbours contains a bad value, or if any of the
C	coordinates is more than one bin width outside the index ranges, then the value
C	BadR4() is returned (see FLINT).
C MODIFICATION HISTORY:
C	MAY-1997, Paul Hick (UCSD; pphick@ucsd.edu)
C-
	    real	F3D(nLng,nLat,nRad)
	    real	XC(N)
	    real	XL(N)
	    real	RP(N)
	    real	FF(N)

	integer		ND(3)
	real		PP(3)

	include		'mapcoordinates.h'

	ND(1) = nLng
	ND(2) = nLat
	ND(3) = nRad

	do I=1,N
	    PP(1) = XCvar(XC(I))
	    PP(2) = XLindx(XL(I))
	    PP(3) = RRindx(RP(I))
	    FF(I) = FLINT(-3,ND,F3D,PP,0.00002)	! Minus sign forces check for bad values
	end do

	return
	end