label	IN:	Label describing the data
	unit	IN:	Unit to be used with the data
	format	IN:	Format to be used in displaying the data
	coordsys	IN:	Coordinate system of the data

	Purpose	Sets the label, unit, format, and coordinate system for the next dataset written to file.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.

	FORTRAN	integer function dssdast(label, unit, format, coordsys)
		character*(*) label, unit, format, coordsys