function str = greg2str(jd,dateform)
% STR = GREG2STR(JD,DATEFORM)
% converts a date vector in Signell's format (either a M by 6 gregorian
% date or julian days as created by julian.m) to a string matrix using 
% the format specified by DATEFORM (as defined by DATESTR)
%
% Default DATEFORM is 1
%
% John Wilkin 17 Feb 1999

if nargin < 2
   dateform = 1;
end

if size(jd,2)==1
   % assume input is in julian days
   str = datestr(jdrps2jdmat(jd),dateform);
else
   % assume input is in gregorian format [year mon day hr min sec]
   if size(jd,2)==3
      % assume hr min sec is missing, pad with zeros so that julian works
      jd = [jd zeros([size(jd,1) 3])];
   end  
   str = datestr(jdrps2jdmat(julian(jd)),dateform);
end