NAME:
    decstr
 PURPOSE: (one line)
    Convert declination in radians to an ASCII string.
 DESCRIPTION:

 CATEGORY:
    Astronomy
 CALLING SEQUENCE:
    decstr, declination, places, str
 INPUTS:
    declination - Declination, in radians, to be converted to a string.  May
                  a vector, in which case the output will be a vector.
    places      - Resolution of output string.
             = -7     nearest hour.                    +DD
             = -6     nearest 30 minutes.              +DD:(00,30)
             = -5     nearest 15 minutes.              +DD:(00,15,30,45)
             = -4     nearest 10 minutes.              +DD:M0
             = -3     nearest 5 minutes.               +DD:M(0,5)
             = -2     nearest minute.                  +DD:MM
             = -1     nearest ten seconds.             +DD:MM:S0
             =  0     nearest second.                  +DD:MM:SS
             =  1     nearest tenth of a second.       +DD:MM:SS.s
             =  2     nearest hundredth of a second.   +DD:MM:SS.ss
             =  3     nearest thousandth of a second.  +DD:MM:SS.sss
 OPTIONAL INPUT PARAMETERS:

 KEYWORD PARAMETERS:
    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 declination.
 COMMON BLOCKS:

 SIDE EFFECTS:

 RESTRICTIONS:

 PROCEDURE:
    Declination (in the range [-pi/2,pi/2]) is converted to a string.
    The sign of the declination is always provided and there are no imbedded
    blanks.  PLACES indicates the reported precision of the string.
    Calls external routine radtodms.
 MODIFICATION HISTORY:
  Copyright (C) 1987,91, by Marc W. Buie
  Version dated 91/8/5
      Ported by Doug Loucks, Lowell Observatory, August 11, 1993, from the
         C-Language version written by Marc Buie.
  2003/05/09, MWB, added SEPCHAR keyword