function carr2jd, carr
;
; Given a scalar or array of Carrington Solar rotation numbers,
; return the corresponding Julian Day Numbers.
;
; B. Knapp, 1996-01-31, 1999-06-25, 1999-08-26 (rename from carr2ut)
;
; RCS Data:
;
; $Header: /home/betelgeuse/knapp/idllib/astronomy/RCS/carr2jd.pro,v 1.2 2001/01/02 21:54:29 knapp Exp knapp $
;
; $Log: carr2jd.pro,v $
; Revision 1.2  2001/01/02 21:54:29  knapp
; Change to new Fortran shareable object library.
;
; Revision 1.1  1999/12/03 00:18:35  knapp
; Initial revision
;
; Print usage?
  n = n_elements( carr )
  if n eq 0 then begin
     print, '     jd = carr2jd( carr )'
     return, ' '
  endif
;
; Use 32-bit or 64-bit shareable object library?
  mbits = ((!version.release ge 5.4) ? !version.memory_bits : 32)
  dll = getenv('bgkroot')+string(mbits,"('/lib/astron',i2,'.so')")
;
; Define output and then call the Fortran subroutine
  carr_loc = double( carr )
  jd = dblarr( n )
  result = call_external( dll, 'carr2ut_arg_', n, carr_loc, jd )
;
; Return scalar or array, according to argument carr
  if (size( carr ))[0] eq 0 then $
     return, jd[0] $
  else $
     return, jd
  end