C+
C NAME:
C	MkV2D
C PURPOSE:
C	Make a density map from a velocity map using the constant momentum
C	flux assumption
C CATEGORY:
C	Data processing
C CALLING SEQUENCE:
	subroutine MkV2D(N,VV,DD,V0)
C INPUTS:
C	N		integer		# data points
C	VV(N)		real		Velocity map
C	V0		real		V0^2 is the momentum flux nvr^2
C					at 1 AU. If nr^2 at 1 AU is 1
C					then V0 is the velocity at 1 AU 
C OUTPUTS:
C	DD(N)		real		normalized density nr^2
C CALLS:
C	BadR4
C PROCEDURE:
C >	It is assumed that the momentum flux is independent of 
C	heliocentric distance (not only independent of V at a specific
C	distance).
C >	Bad values (indicated by BadR4()) are not processed
C MODIFICATION HISTORY:
C	MAY-1999, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
C-
	    integer	N
	    real	VV(N)
	    real	DD(N)	! Velocity and density
	    real	V0

	Bad = BadR4()

	F0 = V0*V0			! Momentum flux at 1 AU

	do I=1,N
	    if (VV(I) .eq. Bad) then
		DD(I) = Bad
	    else
		DD(I) = F0/(VV(I)*VV(I))! Normalized density
	    end if
	end do

	return
	end