C+
C NAME:
C	GTODEN
C PURPOSE:
C	Used by EGIPSY to create density maps
C CALLING SEQUENCE:
	function GTODEN(IDFNC,G)
C INPUTS:
C	IDFNC		integer		ID for indentifying conversion formulae
C					if < 0 in GTODEN the inverse is applied
C	G		real		G-value to be converted
C OUTPUTS:
C	GTODEN		real		Calculated density
C CALLS:
C	BadR4
C SEE ALSO:
C	STRGTODEN, NRGTODEN
C PROCEDURE:
C	To add additional conversions from G value to density, do the following
C	(the places where these changes should be made is indicated in the code)
C > 1.	Add code for the conversion. This would look like:
C
C	else if (IDFNC .eq. ?) then
C	    <more code>
C	    GTODEN = <return value for density>
C	else if (IDFNC .eq. -?) then
C	    <more code>
C	    GTODEN = <return value for G-value from inverse function>
C
C	? stands for the next higher IDFNC value not yet in use
C > 2.	Add a string descriptor for the function. This would look like:
C
C	else if (IDFNC .eq. ?) then
C	    cStr = '<string desciptor>'
C
C	? is the same value as the one in the previous step
C
C > 3.	Increase NRGTODEN. The line defining the new NRGTODEN will usually be:
C
C	NRGTODEN = ?
C
C	where ? again is the same value as in the previous steps
C MODIFICATION HISTORY:
C	MAY-1994, Paul Hick (UCSD)
C-
	    integer	IDFNC
	    real	G

	Bad = BadR4()

	if (G .eq. Bad) then
	    GTODEN = Bad

	else if (IDFNC .eq. 0) then
	    GTODEN = G

	else if (IDFNC .eq.  1) then
	    GTODEN = 9.0*G*G

	else if (IDFNC .eq. -1) then
	    GTODEN = sqrt(G/9.)

	else if (IDFNC .eq.  2) then
	    GTODEN = 10.4*G**3.4

	else if (IDFNC .eq. -2) then
	    GTODEN = (G/10.4)**(1./3.4)

	else if (IDFNC .eq.  3) then
	    GTODEN = 9.5*G**5.1

	else if (IDFNC .eq. -3) then
	    GTODEN = (G/9.5)**(1./5.1)
					! 1. Insert other conversions here !!!
	else
	    GTODEN = Bad

	end if

	return
	end