title check that distance and "print flux earth" commands work 
c
c commands controlling continuum =========
c luminosity in ionizing radiation, this and distance
c were chosen so that flux at earth assocated with total
c luminoisity of object is 1 erg cm-2 s-1 
luminosity 40
laser 2
c
c commands for density & abundances =========
hden 4
init file "honly.ini"
c
c commands controlling geometry  =========
stop zone 1
radius 17
c
c other commands for details     =========
distance 19.450395
constant temperature 4
c
c commands controlling output    =========
c give flux at Earth
print lines, flux at Earth
save overview "func_distance.ovr"
save performance "func_distance.per"
save monitors "func_distance.asr" 
c
c commands giving the monitors    =========
monitor line luminosity "inci" 0 0 
c func_distance.in 
c class function 
c ========================================
c 

Normally the code predicts the intensity or luminosity of
the emission lines.  This test confirms that it can predict
the flux recieved at the Earth instead.  The model is the simplest
and fastest that can be computed - a H-only constant temperature
single zone.  The total luminosity is set to 1e40 erg/s, and the
ionization source is a laser at 2 ryd.  With these set, the
total luminosity in ionizing radiation, the total luminoisity in
the incident continuum (the emission line labeled "Inci 0") will be 1e40.

The code will predict the flux at the Earth if both the distance to the
oject is specified with the distance command, and this is requested with
the print flux earth command.  The distance was chosen so that the
total flux at the Earth will be 1 erg/s.  This is asserted at the
end of the calculation.

