NAME:
    rastr
 PURPOSE: (one line)
    Convert RA in radians to hours, minutes, and seconds (ASCII string).
 DESCRIPTION:

 CATEGORY:
    Astronomy
 CALLING SEQUENCE:
    rastr, radians, places, str, carry
 INPUTS:
  ra     - Right Ascension, in radians, to be converted to a string.
             May a vector, in which case the outputs will be vectors.
  places - output format and precision (see cvtsixty).
OPTIONAL INPUT PARAMETERS:

 KEYWORD INPUT PARAMETERS:
    DEGREES - Flag, if set it means the input is in decimal degrees.
    SEPCHAR - Separator character for the fields in the position.
                 Default=':'.  Warning, if you do not use ':' then the
                 string may not be parsable by raparse.
 OUTPUTS:
    str   - Output string for the converted right ascension.
    carry - Flag that indicates ra rolled over after rounding.
 KEYWORD OUTPUT PARAMETERS:
   ERROR - Flag (scalar or vector), set if an error was seen.
 COMMON BLOCKS:

 SIDE EFFECTS:

 RESTRICTIONS:

 PROCEDURE:
    Right ascension is reduced to the range [0,24) then converted to a string.
    There are no imbedded blanks.
 MODIFICATION HISTORY:
  1993/07/15, Doug loucks, Lowell Observatory, July, 1993, ported from the
         C-Language version written by Marc Buie.
  1997/07/14, MWB, added places=4
  1999/01/12, MWB, added places = -8
  2001/11/04, MWB, fixed bug in places=-7 case
  2003/05/09, MWB, added SEPCHAR keyword
  2009/04/26, MWB, converted to use new CVTSIXTY routine