C+
C NAME:
C	CvG2D
C PURPOSE:
C	Convert from g^2 to normalized density nr^2
C CATEGORY:
C	Tomography
C CALLING SEQUENCE:
	subroutine CvG2D(PWN,N,G2,DD)
C INPUTS:
C	PWN	real
C	N	integer		# values to be converted
C				N < 0 : check for bad values (BadR4())
C	G2(N)	real		g^2 values
C OUTPUTS:
C	DD(N)	real		normalized densities
C CALLS:
C	BadR4
C PROCEDURE:
C	The relation between g^2 and normalized density:
C		G2 = DD^(2*PWN)
C	If N < then bad values in the output array will also be
C	bad in the output array.
C MODIFICATION HISTORY:
C	MAY-1999, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
C-
	    real	PWN
	    integer	N
	    real	G2(*)
	    real	DD(*)

	Bad = BadR4()

	P = 1./(2.*PWN)
	do I=1,abs(N)
	    if (N .gt. 0 .or. G2(I) .ne. Bad) then
		DD(I) = G2(I)**P
	    else
		DD(I) = Bad
	    end if
	end do

	return
	end