Exporting CLASS Spectra through FITS

   1  set angle sec
   2  file in co21.30m
   3  find /range -2 2 -2 2
   4  get f
   5  set fits mode spectrum
   6  fits write single.fits
   7  find /range -2 2 -2 2
   8  fits write index.fits /mode index

1. Angles are expressed in arcseconds.
2. Open the .30m file.
3. Build the index.
4. Store the first spectrum in R memory.
5. Default mode for writing FITS is set to single spectrum.
6. Write the R memory in FITS format file 'single.fits'.
7. Re-build the index.
8. Write the whole index in FITS format file 'index.fits'.